The document contains exam questions and answers related to hydrocarbons that can be used as fuels. Some key details include:
- Butane is a major component of LPG, which stands for liquefied petroleum gas.
- Methane is a major component of natural gas. Mercaptans are often added to natural gas to give it an odor to detect leaks. Methane's release contributes to the greenhouse effect and global warming.
- The heat of combustion of butane is calculated to be -2881 kJ/mol based on heats of formation of products and reactants.
The document discusses an overview of the petroleum refining process. It begins with an introduction and overview, then covers topics like crude oils, products, crude oil distillation, hydrotreatment, gas processing, and other refining units. It provides information on the key steps in refining crude oil into useful products like gasoline, diesel and jet fuels. These include atmospheric and vacuum distillation to separate components by boiling point, along with additional processing units like hydrotreaters, catalytic crackers, reformers and alkylation units for upgrading. The goal of refineries is to maximize production of transportation fuels while meeting product quality specifications.
The document discusses the process of oil refining. Crude oil enters the refinery and is separated into fractions through fractional distillation in distillation towers. It then undergoes additional processes like heating, cooling, and chemical processes. The fractions are treated to remove impurities and blended to produce useful products like gasoline, diesel, kerosene, and others which are then stored for shipping and distribution.
After crude oil is desalted and dehydrated, it is separated into fractions through distillation. However, the distilled fractions cannot be used directly and require further processing due to differences between crude oil properties and market needs. The complexity of refining processes is also due to environmental regulations that require cleaner products. Distillation involves heating crude oil to separate it based on boiling points, but the distilled fractions need additional conversion processes before they can be used or sold.
The document is a 2008 handbook from Hydrocarbon Processing that provides information on refining processes. It reflects advancements in licensed refining technologies, catalysts, and equipment. Refiners must balance investments and strategies to optimize profitability while producing cleaner transportation fuels for a global market. The handbook is a catalog of established and emerging refining technologies that can be applied to existing and new refineries. It provides expanded descriptions and information for various refining operations and processes.
This document summarizes a research project modeling a carbon dioxide gas absorber using methyl diethanol amine (MDEA). The research involved developing mathematical models of the absorber to predict variations in CO2 concentration and temperatures across the column. The models were implemented in MATLAB and results were validated using plant data. Simulation results showed good agreement with plant data and provided insight into how varying process parameters like MDEA concentration and gas flow rate affect absorber performance. The research concluded the developed models accurately modeled the absorber and recommended future work study the regeneration section and residence time dependence.
This document describes gas sweetening processes used to remove acid gases like H2S and CO2 from natural gas. It focuses on chemical absorption processes using alkanolamine solvents like MEA, DGA, DEA, and MDEA in aqueous solutions. The general process involves absorbing acid gases from the feed gas in an absorber column, regenerating the solvent in a regenerator column, and recycling the regenerated solvent. Key unit operations discussed include the absorber, flash drum, amine/amine heat exchanger, regenerator, reboiler, and condenser. Process conditions and equipment details are provided for the typical operation of each unit.
This presentation details out all the process in an Oil Refinery. If you are looking to have a hawk eye view of all the oil refinery process, this presentation will set you on.
Simple explained.
The document discusses an overview of the petroleum refining process. It begins with an introduction and overview, then covers topics like crude oils, products, crude oil distillation, hydrotreatment, gas processing, and other refining units. It provides information on the key steps in refining crude oil into useful products like gasoline, diesel and jet fuels. These include atmospheric and vacuum distillation to separate components by boiling point, along with additional processing units like hydrotreaters, catalytic crackers, reformers and alkylation units for upgrading. The goal of refineries is to maximize production of transportation fuels while meeting product quality specifications.
The document discusses the process of oil refining. Crude oil enters the refinery and is separated into fractions through fractional distillation in distillation towers. It then undergoes additional processes like heating, cooling, and chemical processes. The fractions are treated to remove impurities and blended to produce useful products like gasoline, diesel, kerosene, and others which are then stored for shipping and distribution.
After crude oil is desalted and dehydrated, it is separated into fractions through distillation. However, the distilled fractions cannot be used directly and require further processing due to differences between crude oil properties and market needs. The complexity of refining processes is also due to environmental regulations that require cleaner products. Distillation involves heating crude oil to separate it based on boiling points, but the distilled fractions need additional conversion processes before they can be used or sold.
The document is a 2008 handbook from Hydrocarbon Processing that provides information on refining processes. It reflects advancements in licensed refining technologies, catalysts, and equipment. Refiners must balance investments and strategies to optimize profitability while producing cleaner transportation fuels for a global market. The handbook is a catalog of established and emerging refining technologies that can be applied to existing and new refineries. It provides expanded descriptions and information for various refining operations and processes.
This document summarizes a research project modeling a carbon dioxide gas absorber using methyl diethanol amine (MDEA). The research involved developing mathematical models of the absorber to predict variations in CO2 concentration and temperatures across the column. The models were implemented in MATLAB and results were validated using plant data. Simulation results showed good agreement with plant data and provided insight into how varying process parameters like MDEA concentration and gas flow rate affect absorber performance. The research concluded the developed models accurately modeled the absorber and recommended future work study the regeneration section and residence time dependence.
This document describes gas sweetening processes used to remove acid gases like H2S and CO2 from natural gas. It focuses on chemical absorption processes using alkanolamine solvents like MEA, DGA, DEA, and MDEA in aqueous solutions. The general process involves absorbing acid gases from the feed gas in an absorber column, regenerating the solvent in a regenerator column, and recycling the regenerated solvent. Key unit operations discussed include the absorber, flash drum, amine/amine heat exchanger, regenerator, reboiler, and condenser. Process conditions and equipment details are provided for the typical operation of each unit.
This presentation details out all the process in an Oil Refinery. If you are looking to have a hawk eye view of all the oil refinery process, this presentation will set you on.
Simple explained.
This document discusses catalytic reforming and hydrocracking processes. It provides details on:
- Catalytic reforming converts low octane naphtha into high octane reformates through reactions like dehydrogenation and dehydrocyclization.
- Hydrocracking breaks down heavier hydrocarbon molecules into simpler molecules like gasoline and kerosene using hydrogen and catalysts at high pressures.
- Both processes upgrade petroleum fractions through chemical reactions like cracking, isomerization and hydrogenation to produce more valuable products like gasoline and jet fuel.
The document describes the chlor-alkali process for producing chlorine and sodium hydroxide through the electrolysis of sodium chloride brine. Key aspects include:
- Sodium chloride brine is purified through processes like precipitation to remove impurities before electrolysis.
- During electrolysis, chlorine gas is produced at the anode, sodium hydroxide at the cathode, and hydrogen as a byproduct. A membrane separates the anode and cathode compartments.
- Weak brine leaving the anode contains dissolved chlorine which is removed through processes like acidification before recycling. Sodium hydroxide product is cooled and may be concentrated.
Visbreaking and delayed coking are processes used in oil refineries. Visbreaking uses heat to crack large hydrocarbon molecules and reduce viscosity, producing gas, naphtha, and distillates. It occurs in either coil or soaker units. Delayed coking thermally cracks residual oil in parallel furnaces and drums, producing coker gas oil and petroleum coke while maximizing distillates and minimizing coke yield. Problems include fouling, coke formation, and asphaltene precipitation, which can be addressed using high pressure heat exchangers.
The document discusses methods for removing sulfur from crude oil. Sulfur is present as both organic and inorganic compounds in crude oil. The most common removal methods are catalytic desulfurization, chemical desulfurization, physical adsorption of sulfur oxides, and wet sulfuric acid processes. Catalytic desulfurization, also called hydrodesulfurization, uses hydrogen and catalysts at high pressure and temperature to convert sulfur compounds to hydrogen sulfide. Chemical desulfurization methods include treatments with acid chromous chloride or peroxyacetic acid. Physical adsorption uses carbonaceous adsorbents to capture sulfur dioxide from flue gases.
Heavy oil processing involves upgrading heavy crude oils and residues through various refining processes. Heavy oils are found globally and will be an increasingly important source of crude supply. They are more viscous, contain higher concentrations of contaminants, and are more difficult and costly to produce and refine than conventional oils. Key upgrading processes include solvent deasphalting to separate heavy fractions, various hydrotreating methods to remove contaminants, and lube oil processing steps like solvent extraction, dewaxing, and hydrofinishing to produce base oils and fuels from heavy feedstocks.
This master's thesis assesses the feasibility of using sour and acid gas miscible flooding in Reservoir X. It includes a literature review on CO2/H2S miscible flooding and case studies. Compositional and PVT data from Reservoir X is presented. CMG WinProp software is used to simulate multiple contacts between CO2/H2S solvent mixtures and Reservoir X oil. Minimum miscibility pressures are determined for different solvent mixtures, as well as the oil swelling factor and changes in oil viscosity and density. The results indicate whether sour and acid gas miscible flooding is viable for Reservoir X.
This document provides an overview of petrochemicals from the website ChemicalEngineeringGuy.com. It begins with definitions of petrochemicals and describes the petrochemical industry and various petrochemical products. It then covers petrochemical raw materials, groups by carbon number, processes, plants and facilities. The document aims to provide foundational knowledge about petrochemicals, including key terminology, production pathways, common intermediates and final products. It also references additional resources to learn more about specific topics in petrochemical engineering.
The document describes a process for producing acetic acid from methane using three steps. First, methane is oxidized in a reactor to produce methanol and acetic acid. The products are separated using flash distillation, yielding methanol and acetic acid. The methanol is then converted to additional acetic acid in a carbonylation reactor using a rhodium catalyst. Mass and energy balances were performed on the overall process. The reactors and separation equipment are also described.
1. Distillation is the first step in refining crude oil, where it is heated and separated into fractions based on boiling points in a fractionation column.
2. Before distillation, crude oil undergoes desalting to remove water and salts, and preheating through heat exchangers. It is then sent to a furnace and pre-flash vessel to further vaporize components.
3. Fractions are drawn off from different parts of the fractionation column for further processing. Lighter fractions condense higher in the column, while heavier fractions condense lower down.
Thermal cracking is a refinery process that breaks larger hydrocarbon molecules into smaller molecules like gasoline. The presentation discusses various aspects of thermal cracking including:
1. The necessity of cracking to produce more gasoline from heavier crude oil fractions.
2. The main types of cracking - thermal cracking and catalytic cracking. Thermal cracking uses high temperatures without a catalyst.
3. Key thermal cracking processes like Dubbs, pyrolysis, visbreaking, and coking which use different temperatures and pressures to produce different product yields.
4. The thermal cracking reactions of decomposition, hydrogenation, polymerization, and cyclization that alter the hydrocarbon molecules.
5. Commercial thermal cracking units and how they operate to continuously
The document discusses hydrogen production via steam reforming of natural gas. Steam reforming involves four steps: reforming, shift conversion, gas purification, and methanation. It produces hydrogen at high efficiency and is the lowest cost production method currently available. However, it also produces carbon dioxide as a byproduct. Newer steam reforming plants use pressure swing absorption to produce 99.99% pure hydrogen. While steam reforming is an efficient process, it contributes to carbon dioxide emissions, so methods to capture and store the CO2 are being investigated.
SMR PRE-REFORMER DESIGN
Case Study #0618416GB/H
Contents
1. SMR Pre-Reformer Design
2. Inlet Baffle Design
3. Outlet Collector
4. Hold Down Grating
5. Floating Hold Down Screen
6. Catalyst Drop Out Nozzle
7. Thermowell Detail
8. Technical Performance requirements
9. SMR Pre-Reformer Isolation
Technical Review and Commentary on Proposed Design
APPENDIX
A. Operating / Mechanical Data
B. Materials Specifications
C. Fabrication and Inspection Requirements
D. Weights
E. Nozzle Data
F. Instrument Connections
G. Manholes
The document discusses monitoring programs for critical equipment in ammonia plants to improve reliability and uptime. It outlines key performance indicators to monitor for various units, such as the primary reformer, secondary reformer, and shift converters. Monitoring parameters like temperatures, pressures, emissions and efficiencies can help identify problems early before catastrophic failures and keep the plant running optimally.
Desulfurization is the process of removing sulfur from substances like natural gas, coal, oil, and flue gas to reduce sulfur dioxide emissions. There are several common methods for desulfurization, including hydrodesulfurization, chemical desulfurization, physical adsorption of sulfur oxides, and wet sulfuric acid processes. Hydrodesulfurization involves heating a mixture of oil and hydrogen gas over a catalyst to break sulfur-carbon bonds and form hydrogen sulfide. Chemical desulfurization uses oxidizing agents like organic peroxides to remove sulfur from crude oil. Physical adsorption uses adsorbents like activated carbon or plant materials to capture sulfur oxides from flue gases or aqueous solutions.
Vacuum distillation is used in oil refineries to further separate and refine the bottoms leftover from atmospheric distillation. It allows for distillation of compounds with high boiling points without thermal cracking by reducing the pressure and lowering the boiling points. Vacuum distillation units in refineries can have columns up to 14 meters wide and 50 meters tall, processing up to 25,400 cubic meters of feed per day. This additional refinement produces more valuable petroleum products from the heavier fractions of crude oil.
This presentation summarizes the hydrotreating process. Hydrotreating reduces sulfur, nitrogen and aromatics in petroleum feeds using hydrogen. It has various applications including desulfurizing naphtha, kerosene, gas oil and fuel oils. The process involves reacting feeds over catalysts in fixed beds to hydrogenate contaminants like sulfur, nitrogen and olefins. Typical hydrotreating removes these through reactions like desulfurization and denitrogenation. The presentation describes specific hydrotreating processes for distillate desulfurization and kerosene smoke point improvement.
all process involve in petroleum to get final products from crude oil like LPG, petrol, diesel, jet fuel, kerosene,neptha, heavy neptha, coke and petroleum products
Amine gas treating is a process that uses aqueous solutions of alkanolamines like monoethanolamine to remove hydrogen sulfide and carbon dioxide from gases. The process involves an absorber unit where the amine solution absorbs the acid gases from the sour gas stream, producing a sweetened gas. The rich amine is then regenerated in a stripper, producing a lean amine that is recycled and an acid gas stream that is usually sent to a Claus process to produce elemental sulfur. Common amines used include MEA, DEA, and MDEA.
The document discusses the chemical alkynes, specifically ethyne (C2H2). It describes the laboratory preparation of ethyne from calcium dicarbide and water, which produces ethyne gas. Ethyne is colorless, insoluble in water but soluble in nonpolar solvents, and burns with a very hot, smoky flame when combusted. It can be used to cut and weld steel in oxy-acetylene torches. The document also discusses the manufacture and uses of hydrogen, including from natural gas reforming and electrolysis of water, and its use in the Haber process and as a fuel. Fuel cells that use hydrogen are also mentioned.
The document discusses atomic structure and spectra. It begins by introducing emission and absorption spectra of hydrogen atoms and defines the Balmer series. It then explains that line spectra provide evidence for discrete energy levels in atoms. The document discusses atomic orbitals and electronic configurations, including how electrons fill different sub-levels based on the Aufbau principle, Hund's rule, and Pauli's exclusion principle. Spectroscopes are described as devices used to observe emission spectra of elements.
This document discusses catalytic reforming and hydrocracking processes. It provides details on:
- Catalytic reforming converts low octane naphtha into high octane reformates through reactions like dehydrogenation and dehydrocyclization.
- Hydrocracking breaks down heavier hydrocarbon molecules into simpler molecules like gasoline and kerosene using hydrogen and catalysts at high pressures.
- Both processes upgrade petroleum fractions through chemical reactions like cracking, isomerization and hydrogenation to produce more valuable products like gasoline and jet fuel.
The document describes the chlor-alkali process for producing chlorine and sodium hydroxide through the electrolysis of sodium chloride brine. Key aspects include:
- Sodium chloride brine is purified through processes like precipitation to remove impurities before electrolysis.
- During electrolysis, chlorine gas is produced at the anode, sodium hydroxide at the cathode, and hydrogen as a byproduct. A membrane separates the anode and cathode compartments.
- Weak brine leaving the anode contains dissolved chlorine which is removed through processes like acidification before recycling. Sodium hydroxide product is cooled and may be concentrated.
Visbreaking and delayed coking are processes used in oil refineries. Visbreaking uses heat to crack large hydrocarbon molecules and reduce viscosity, producing gas, naphtha, and distillates. It occurs in either coil or soaker units. Delayed coking thermally cracks residual oil in parallel furnaces and drums, producing coker gas oil and petroleum coke while maximizing distillates and minimizing coke yield. Problems include fouling, coke formation, and asphaltene precipitation, which can be addressed using high pressure heat exchangers.
The document discusses methods for removing sulfur from crude oil. Sulfur is present as both organic and inorganic compounds in crude oil. The most common removal methods are catalytic desulfurization, chemical desulfurization, physical adsorption of sulfur oxides, and wet sulfuric acid processes. Catalytic desulfurization, also called hydrodesulfurization, uses hydrogen and catalysts at high pressure and temperature to convert sulfur compounds to hydrogen sulfide. Chemical desulfurization methods include treatments with acid chromous chloride or peroxyacetic acid. Physical adsorption uses carbonaceous adsorbents to capture sulfur dioxide from flue gases.
Heavy oil processing involves upgrading heavy crude oils and residues through various refining processes. Heavy oils are found globally and will be an increasingly important source of crude supply. They are more viscous, contain higher concentrations of contaminants, and are more difficult and costly to produce and refine than conventional oils. Key upgrading processes include solvent deasphalting to separate heavy fractions, various hydrotreating methods to remove contaminants, and lube oil processing steps like solvent extraction, dewaxing, and hydrofinishing to produce base oils and fuels from heavy feedstocks.
This master's thesis assesses the feasibility of using sour and acid gas miscible flooding in Reservoir X. It includes a literature review on CO2/H2S miscible flooding and case studies. Compositional and PVT data from Reservoir X is presented. CMG WinProp software is used to simulate multiple contacts between CO2/H2S solvent mixtures and Reservoir X oil. Minimum miscibility pressures are determined for different solvent mixtures, as well as the oil swelling factor and changes in oil viscosity and density. The results indicate whether sour and acid gas miscible flooding is viable for Reservoir X.
This document provides an overview of petrochemicals from the website ChemicalEngineeringGuy.com. It begins with definitions of petrochemicals and describes the petrochemical industry and various petrochemical products. It then covers petrochemical raw materials, groups by carbon number, processes, plants and facilities. The document aims to provide foundational knowledge about petrochemicals, including key terminology, production pathways, common intermediates and final products. It also references additional resources to learn more about specific topics in petrochemical engineering.
The document describes a process for producing acetic acid from methane using three steps. First, methane is oxidized in a reactor to produce methanol and acetic acid. The products are separated using flash distillation, yielding methanol and acetic acid. The methanol is then converted to additional acetic acid in a carbonylation reactor using a rhodium catalyst. Mass and energy balances were performed on the overall process. The reactors and separation equipment are also described.
1. Distillation is the first step in refining crude oil, where it is heated and separated into fractions based on boiling points in a fractionation column.
2. Before distillation, crude oil undergoes desalting to remove water and salts, and preheating through heat exchangers. It is then sent to a furnace and pre-flash vessel to further vaporize components.
3. Fractions are drawn off from different parts of the fractionation column for further processing. Lighter fractions condense higher in the column, while heavier fractions condense lower down.
Thermal cracking is a refinery process that breaks larger hydrocarbon molecules into smaller molecules like gasoline. The presentation discusses various aspects of thermal cracking including:
1. The necessity of cracking to produce more gasoline from heavier crude oil fractions.
2. The main types of cracking - thermal cracking and catalytic cracking. Thermal cracking uses high temperatures without a catalyst.
3. Key thermal cracking processes like Dubbs, pyrolysis, visbreaking, and coking which use different temperatures and pressures to produce different product yields.
4. The thermal cracking reactions of decomposition, hydrogenation, polymerization, and cyclization that alter the hydrocarbon molecules.
5. Commercial thermal cracking units and how they operate to continuously
The document discusses hydrogen production via steam reforming of natural gas. Steam reforming involves four steps: reforming, shift conversion, gas purification, and methanation. It produces hydrogen at high efficiency and is the lowest cost production method currently available. However, it also produces carbon dioxide as a byproduct. Newer steam reforming plants use pressure swing absorption to produce 99.99% pure hydrogen. While steam reforming is an efficient process, it contributes to carbon dioxide emissions, so methods to capture and store the CO2 are being investigated.
SMR PRE-REFORMER DESIGN
Case Study #0618416GB/H
Contents
1. SMR Pre-Reformer Design
2. Inlet Baffle Design
3. Outlet Collector
4. Hold Down Grating
5. Floating Hold Down Screen
6. Catalyst Drop Out Nozzle
7. Thermowell Detail
8. Technical Performance requirements
9. SMR Pre-Reformer Isolation
Technical Review and Commentary on Proposed Design
APPENDIX
A. Operating / Mechanical Data
B. Materials Specifications
C. Fabrication and Inspection Requirements
D. Weights
E. Nozzle Data
F. Instrument Connections
G. Manholes
The document discusses monitoring programs for critical equipment in ammonia plants to improve reliability and uptime. It outlines key performance indicators to monitor for various units, such as the primary reformer, secondary reformer, and shift converters. Monitoring parameters like temperatures, pressures, emissions and efficiencies can help identify problems early before catastrophic failures and keep the plant running optimally.
Desulfurization is the process of removing sulfur from substances like natural gas, coal, oil, and flue gas to reduce sulfur dioxide emissions. There are several common methods for desulfurization, including hydrodesulfurization, chemical desulfurization, physical adsorption of sulfur oxides, and wet sulfuric acid processes. Hydrodesulfurization involves heating a mixture of oil and hydrogen gas over a catalyst to break sulfur-carbon bonds and form hydrogen sulfide. Chemical desulfurization uses oxidizing agents like organic peroxides to remove sulfur from crude oil. Physical adsorption uses adsorbents like activated carbon or plant materials to capture sulfur oxides from flue gases or aqueous solutions.
Vacuum distillation is used in oil refineries to further separate and refine the bottoms leftover from atmospheric distillation. It allows for distillation of compounds with high boiling points without thermal cracking by reducing the pressure and lowering the boiling points. Vacuum distillation units in refineries can have columns up to 14 meters wide and 50 meters tall, processing up to 25,400 cubic meters of feed per day. This additional refinement produces more valuable petroleum products from the heavier fractions of crude oil.
This presentation summarizes the hydrotreating process. Hydrotreating reduces sulfur, nitrogen and aromatics in petroleum feeds using hydrogen. It has various applications including desulfurizing naphtha, kerosene, gas oil and fuel oils. The process involves reacting feeds over catalysts in fixed beds to hydrogenate contaminants like sulfur, nitrogen and olefins. Typical hydrotreating removes these through reactions like desulfurization and denitrogenation. The presentation describes specific hydrotreating processes for distillate desulfurization and kerosene smoke point improvement.
all process involve in petroleum to get final products from crude oil like LPG, petrol, diesel, jet fuel, kerosene,neptha, heavy neptha, coke and petroleum products
Amine gas treating is a process that uses aqueous solutions of alkanolamines like monoethanolamine to remove hydrogen sulfide and carbon dioxide from gases. The process involves an absorber unit where the amine solution absorbs the acid gases from the sour gas stream, producing a sweetened gas. The rich amine is then regenerated in a stripper, producing a lean amine that is recycled and an acid gas stream that is usually sent to a Claus process to produce elemental sulfur. Common amines used include MEA, DEA, and MDEA.
The document discusses the chemical alkynes, specifically ethyne (C2H2). It describes the laboratory preparation of ethyne from calcium dicarbide and water, which produces ethyne gas. Ethyne is colorless, insoluble in water but soluble in nonpolar solvents, and burns with a very hot, smoky flame when combusted. It can be used to cut and weld steel in oxy-acetylene torches. The document also discusses the manufacture and uses of hydrogen, including from natural gas reforming and electrolysis of water, and its use in the Haber process and as a fuel. Fuel cells that use hydrogen are also mentioned.
The document discusses atomic structure and spectra. It begins by introducing emission and absorption spectra of hydrogen atoms and defines the Balmer series. It then explains that line spectra provide evidence for discrete energy levels in atoms. The document discusses atomic orbitals and electronic configurations, including how electrons fill different sub-levels based on the Aufbau principle, Hund's rule, and Pauli's exclusion principle. Spectroscopes are described as devices used to observe emission spectra of elements.
9 environmental chemistry water learning outcomesMartin Brown
This document outlines the learning outcomes for the environmental chemistry section of the Leaving Certificate Chemistry curriculum in Ireland. It covers four topics: 1) the pH scale, 2) hardness in water, 3) water treatment, and 4) water analysis. The key points covered include defining pH and calculating pH of solutions, identifying causes of water hardness and methods for removal, describing water treatment processes like sedimentation and chlorination, and outlining instrumental methods for water analysis including pH meters, atomic absorption spectroscopy, and colorimetry.
Hydrocarbons like crude oil, natural gas, and coal are fossil fuels formed from the remains of ancient marine plants and animals. Methane is a hydrocarbon produced naturally in coal mines, slurry pits, waste dumps, and the digestive tracts of animals, but it poses fire, explosion, and suffocation hazards if it accumulates.
Water undergoes self-ionization in which a small percentage of water molecules dissociate into hydronium (H3O+) and hydroxide (OH-) ions. The concentration of these ions is extremely small and the equilibrium lies very much in the forward direction. The self-ionization of water can be represented by the equilibrium constant Kw, which is equal to the product of the hydronium and hydroxide ion concentrations. Kw is temperature dependent and decreases with increasing temperature. The pH scale was developed to quantify the concentration of hydronium ions in solution and thus indicate whether a solution is acidic, basic, or neutral. pH is defined as the negative logarithm of the hydronium ion concentration
Crude oil is separated into fractions by fractional distillation based on differences in boiling points. The fractions include refinery gas, light gasoline, naphtha, kerosene, gas oil, and residue. These fractions are used to produce fuels like petrol, diesel, and jet fuel. Petrol is a complex mixture of hydrocarbons, mainly alkanes and aromatics. Its octane rating, which indicates its resistance to premature ignition, can be increased through processes like isomerization, dehydrocyclization, and catalytic cracking that produce more branched and cyclic molecules.
This document outlines the key learning outcomes for two topics in Leaving Certificate Chemistry: 8.1 Chemical Equilibrium and 8.2 Le Chatelier's Principle. For 8.1, students should be able to explain concepts related to reversible reactions and chemical equilibrium, write equilibrium constant expressions, and perform calculations involving equilibrium constants. For 8.2, students should be able to state Le Chatelier's principle and use it to predict how concentration, pressure, temperature, and catalysts affect equilibrium position, as demonstrated through experiments on example chemical mixtures. Industrial applications are also discussed.
5.2 structure of aliphatic hydrocarbonsMartin Brown
This document discusses the structure and properties of aliphatic hydrocarbons. It defines aliphatic hydrocarbons as hydrocarbons containing only carbon and hydrogen atoms arranged in straight or branched chains or rings, excluding benzene rings. The three main types of aliphatic hydrocarbons are alkanes, alkenes, and alkynes. Alkanes have the general formula CnH2n+2 and include methane, ethane, propane, etc. Alkenes have the formula CnH2n and contain carbon-carbon double bonds. Alkynes have the formula CnH2n-2 and contain carbon-carbon triple bonds. Physical properties like state, solubility,
This document summarizes water treatment and sewage treatment processes. It describes how surface water is treated through steps like sedimentation, flocculation, filtration, chlorination and fluoridation to remove contaminants. Sewage treatment involves primary, secondary and sometimes tertiary levels to remove solids, break down organic waste biologically, and remove nutrients like nitrates and phosphates. The document also discusses how excess nutrients can cause eutrophication of waterways and pollution from heavy metals and legislation limits their levels.
1 periodic table and atomic structure learning outcomesMartin Brown
This document outlines the learning outcomes for topics covered in the Leaving Certificate Chemistry curriculum in Ireland. It includes learning outcomes for several topics: the periodic table and atomic structure, atomic structure, radioactivity, electronic structure of atoms, and oxidation and reduction. For each topic, it lists the key concepts students should understand and be able to do, such as describe trends in the periodic table, outline the historical development of atomic theory, and define oxidation and reduction in terms of electron transfer.
The document summarizes atomic structure and the development of atomic theory. It discusses key scientists and experiments that led to discoveries such as electrons, protons, neutrons, and the nuclear model of the atom. These include Thomson's work on cathode rays, Rutherford's gold foil experiment, and Chadwick's discovery of the neutron. The document also covers atomic number, mass number, isotopes, relative atomic mass, and how mass spectrometry is used to determine relative atomic masses.
The document discusses hard water and its causes. Hard water is water that does not easily form soap lathers, due to the presence of calcium and magnesium ions that react with soap. There are two types of hardness: temporary hardness caused by calcium and magnesium bicarbonates that can be removed by boiling, and permanent hardness caused by calcium and magnesium chlorides and sulfates that cannot be removed by boiling. Methods for softening hard water include using ion exchange resins that replace calcium and magnesium ions with sodium ions.
The document summarizes key information about radioactivity, including the discoveries of Becquerel, Marie Curie, and Pierre Curie in the late 19th century. It describes the three main types of radiation (alpha, beta, gamma) and provides examples of common radionuclides that emit each type, such as americium-241, carbon-14, and cobalt-60. Uses of radioisotopes discussed include carbon-14 dating, cobalt-60 for cancer treatment, and food irradiation. The document also covers half-life, nuclear reactions, and distinguishes between chemical and nuclear processes.
The document contains sample exam questions from various years on topics related to atomic structure, the periodic table, ionization energies, atomic spectra, bonding, and the historical experiments that led to discoveries about atomic structure. It includes multiple choice and open response questions testing definitions, explanations of trends, interpretations of data, and descriptions of experiments. The questions would require a strong understanding of foundational atomic and molecular concepts as well as the ability to apply this knowledge to analyze new situations.
Benzene is an aromatic hydrocarbon with a planar hexagonal ring structure. Each carbon atom in the ring forms four bonds - one with a hydrogen atom and three sigma bonds with the other carbon atoms in the ring. The sixth valence electron of each carbon is delocalized and shared among all six carbon atoms, giving benzene unusual stability and properties compared to other unsaturated hydrocarbons. Aromatic compounds contain a benzene ring in their structure and include benzene itself along with methylbenzene and ethylbenzene. These aromatic hydrocarbons are liquids that are insoluble in water but soluble in non-polar solvents.
The document discusses atomic radii and ionization energy trends across periods and down groups of the periodic table. It explains that atomic radii generally decrease across periods as nuclear charge increases, while increasing down groups as additional electrons occupy farther shells. Ionization energy also typically increases across periods and decreases down groups. Exceptions are noted for beryllium and nitrogen. Evidence for electronic energy levels is shown through successive ionization energies of potassium that indicate full and half-filled shells require more energy to further ionize.
5.4 exothermic and endothermic reactionsMartin Brown
This document discusses exothermic and endothermic reactions. Exothermic reactions release heat, while endothermic reactions absorb heat. Combustion reactions of hydrocarbons like methane and propane are exothermic, producing carbon dioxide, water vapor, and large amounts of heat. The heat of reaction, ΔH, indicates whether a reaction is exothermic (negative ΔH) or endothermic (positive ΔH). Bond energies represent the energy required to break bonds, while heat of combustion measures the heat released from complete combustion. A bomb calorimeter is used to accurately measure heats of combustion by igniting samples in excess oxygen. Hess's law states that the heat change of a reaction depends only on
Environmentatl chemistry water (questions and answers)Martin Brown
This document contains exam questions from 2009-2002 on the topics of water treatment, water quality testing, acid-base chemistry, and sewage treatment. It asks students to define concepts like conjugate acid-base pairs, calculate pH values, identify chemicals used in water treatment and their purposes, and describe the multi-stage processes involved in treating water and sewage.
1. The document summarizes the history and development of the periodic table, including contributions from Greek philosophers, Boyle, Davy, Moseley, Dobereiner, Newlands, and Mendeleev.
2. It describes the key features and organization of the modern periodic table, including periods, groups, atomic number, valence electrons, and trends in physical/chemical properties for different groups like alkali metals, alkaline earth metals, halogens, noble gases, and transition metals.
3. Specific elements are highlighted from different groups to illustrate trends, including lithium, sodium, potassium, beryllium, barium, calcium, magnesium, strontium, radium, chlorine, brom
The document provides an overview of oxidation and reduction concepts including:
- Oxidation involves loss of electrons while reduction involves gain of electrons.
- Examples of oxidation and reduction reactions are given for sodium-chlorine, magnesium-oxygen, and zinc-copper sulfate.
- Oxidizing and reducing agents are defined as substances that cause oxidation or reduction in other substances.
- The electrochemical series orders metals by their tendency to be oxidized.
- Electrolysis and examples like copper plating and extracting copper from scrap iron using electrolysis are summarized.
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Similar to Section 5 exam questions and answers (20)
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إضغ بين إيديكم من أقوى الملازم التي صممتها
ملزمة تشريح الجهاز الهيكلي (نظري 3)
💀💀💀💀💀💀💀💀💀💀
تتميز هذهِ الملزمة بعِدة مُميزات :
1- مُترجمة ترجمة تُناسب جميع المستويات
2- تحتوي على 78 رسم توضيحي لكل كلمة موجودة بالملزمة (لكل كلمة !!!!)
#فهم_ماكو_درخ
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واخيراً هذهِ الملزمة حلالٌ عليكم وإتمنى منكم إن تدعولي بالخير والصحة والعافية فقط
كل التوفيق زملائي وزميلاتي ، زميلكم محمد الذهبي 💊💊
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Section 5 exam questions and answers
1. Section 5 Exam Questions and Answers
2002 Question 8
The following hydrocarbons can all be used as fuels.
methane (CH4)
butane (C4H10)
2,2,4-trimethylpentane (C8H18)
(a) Butane is a major component of LPG. What do the letters LPG stand for?
(5)
Draw two structural isomers of butane. (6)
(b) Methane is a major component of natural gas. Why are mercaptans often added to natural gas?
What environmental change or effect is associated with the release of methane to the atmosphere?
Apart from leaking gas pipes, name a major source from which methane is released to the atmosphere. (9)
(c) What structural feature of 2,2,4-trimethylpentane results in it having a high octane rating?
Give one other structural feature which increases the octane number of a hydrocarbon.
(6)
(d) Define heat of combustion of a compound.
(6)
(e) The combustion of butane is described by the following balanced equation.
2C4H10(g) +13O2(g) → 8CO2(g) + 10H2O(l)
Calculate the heat of combustion of butane given that the heats of formation of butane, carbon dioxide and water are –
125, –394 and –286 kJ mol-1, respectively.
(18)
2002
Question 8
(a)
LPG: liquefied (liquid) petroleum gas
(5)
(6)
[Accept sticks without Hs put in] (3)
[Accept sticks without Hs put in] (3)
WHY: to give an odour (smell) / to detect leaks (3)
WHAT: greenhouse effect / global warming / reducing ozone damage (3)
SOURCE: fossil fuels / oil / coal / marshes (bogs, paddy fields) / animals (cows, sheep, etc.)
/dumps / slurry / anaerobic decay / compost (3)
FEATURE: branching / short chain
OTHER: ring / branching (unless used above) / aromatic / short chain (if not used above)
DEFINE: heat when 1 mole (3) is burned completely / burned in excess oxygen
–1
CALCUL: – 2881 kJ mol (18)
ΔH = ΔHformation(products) - ΔHformation(reactants)
ΔH = [4 (3) ( – 394) (3)+ 5 (3) (– 286) (3) – (– 125) (3)] = – 2881 kJ mol–1 (3)
OR
[ – 1576 (6) – 1430 (6) + 125 (3)] = – 2881 kJ mol–1 (3)
(b)
(c)
(d)
2003
(3)
(3)
(3)
(18)
Question 10. (a)
Define heat of combustion.
(7)
Propane may be used in gas cylinders for cooking appliances. Propane burns according to the equation
C3H8 + 5O2 3CO2 + 4H2O
(i) The heats of formation of propane, carbon dioxide and water are –104, –394 and –286 kJ mol–1 respectively. Calculate
the heat of combustion of propane.
(12)
(ii) If 500 kJ of energy are needed to boil a kettle of water what mass of propane gas must be burned to generate this
amount of heat? Express your answer to the nearest gram.
(6)
2003
Question 10. (a)
(a)
(i)
(ii)
Define: heat when 1 mole (4) is burned completely / burned in excess oxygen
–1
Calc: ΔH = – 2222 kJ mol
Σ ΔH formation(products) – Σ ΔH formation(reactants) = ΔH
–1
3 × – 394 or – 1182 (3) 4 × – 286 or – 1144 (3) – (–104) /or + 104 / 104 (3) = – 2222 kJ mol (3)
10 g
1 × 500 = 0.225 mol (3) × 44 = 10 (3) OR 44 × 500 (3) = 10 (3)
Note: penalty (– 1) if answer
2222
2222
not rounded off to 10.
(3)
(12)
(6)
2. 2004
Question 6
(a) Define (i) heat of formation of a substance, (ii) octane number of a fuel.
(11)
(b) The combustion of methane is described by the following balanced equation.
CH4(g) + 2O2(g) CO2(g) + 2H2O(l) ΔH = − 890.4 kJ mol-1
The standard heats of formation of carbon dioxide and water are −394 and −286 kJ mol-1 respectively.
Calculate the heat of formation of methane. (12)
(c) Methane is an excellent fuel. Give two properties of methane which account for its usefulness as a fuel.
Natural gas is a rich source of methane. Why are mercaptans often added to natural gas?
(9)
(d) Methane is often found in gas fields which occur in association with crude oil deposits. Crude oil is fractionated in
order to obtain more useful products. Outline clearly how the fractionation process is carried out.
(12)
(e) Identify two structural features of a hydrocarbon fuel which affect its octane number.
(6)
2004
(a)
(b)
(c)
(d)
(e)
Question 6
(i)
(ii)
heat (energy) when 1 mole //of compound formed from its elements
measure of tendency to auto-ignite (knock) or number representing ability of fuel to resist
auto-igniting (knocking)
–1
CALC.: – 75.6 kJ mol
ΔH(reaction) = Σ ΔHf(products) – Σ ΔHf(reactants)
– 890.4 (3) = [ – 394 (3) – 572 (3)] – [ΔHf(methane) + 0]
–1
–
ΔHf(methane) = – 394 – 572 + 890.4 = – 75.6 kJ mol (3)
[Allow 3 marks only for +75.6 kJ mol
1
]
PROPS: high kilogram cal. value (high heat of combustion) / clean (non- polluting) / non-toxic /
relatively cheap/ can be piped Do not accept „easily distributed in tanks‟
ANY TWO: (2 x 3)]
WHY: to give an odour (smell) / to detect leaks / to make safe
OUTLINE: crude oil heated / crude added continuously at bottom /
vapour passes up through column / fractionating tower with trays
fractions condense at different levels depending on their boiling points / high b.p. fractions at
bottom / low higher up /heavier at bottom / lighter at top / or named exemplar to indicate this
[The first three points can be got from a diagram; the last point must be specified in words or clearly
written on the diagram.]
ANY THREE: (6 + 2 x 3)
IDENTIFY: chain length / branching / cyclic / aromatics
ANY TWO: (2 x 3)
(3+2)
(6)
(12)
(6)
(3)
(12)
(6)
2005 Question 6
(a) The octane number of a fuel is described as a measure of the tendency of the fuel to cause knocking, or as a measure of
the tendency of the fuel to resist auto-ignition. This number is found by comparing the combustion of the fuel with the
combustion of a mixture of two reference hydrocarbons using the same standard engine.
(i) Name both of the reference hydrocarbons present in the mixture used when measuring octane number by this
comparison method.
(8)
(ii) State two structural features of a hydrocarbon molecule which contribute to it having a high octane number. (6)
(iii) Lead compounds were used in the past to increase the octane number of fuels. Why are lead compounds unsuitable as
additives for petrol used in modern cars?
(3)
(iv) Identify one additive or type of additive, other than a compound of lead, used to increase the octane number
of fuels.
(3)
(b) There are three structural isomers of the hydrocarbon of formula C5H12. In the case of each of these isomers, draw the
structure of the molecule and give its systematic IUPAC name.
(18)
(c) The combustion of liquid benzene is described by the following equation:
2C6H6(l) + 15O2(g) 12 CO2(g) + 6H2O(l)
Given that the heats of formation of carbon dioxide gas, liquid water and liquid benzene are –394,–286 and
49 kJ mol-1 respectively, calculate the heat of combustion of liquid benzene.
(12)
3. 2005
(a)
Question 6
(i)
(ii)
(iii)
(iv)
(b)
(c)
NAME: 2,2,4-trimethylpentane (isooctane) // heptane (n-heptane) (2 x 4)
STATE: short chain length / branching / ring (cyclic) / aromatic
ANY TWO: (2 x3)
WHY: catalyst poison / destroys catalytic converter
IDENTIFY: oxygenate or methanol or ethanol / methyl-t-butyl ether (MTBE)
CH3CH2CH2CH2CH3 / CH3(CH2) 3CH3 (3) pentane (3)
(CH3) 2CHCH2CH3 / CH3CH2CH(CH3) 2 (3) 2-methylbutane (3)
(CH3) 4C / (CH3) 3CCH3 / (CH3) 2C(CH3) 2 (3) 2,2-dimethylpropane (3)
[Matching of names and formulae are required. In expanded structures, bonds without Hs are
acceptable. Numbers are not required for the methyl branches but, if incorrect numbers are offered
(e.g. 1,2-dimethylpropane), then no marks should be awarded.]
ΔH = Σ ΔH
– Σ ΔH
f(products)
f(reactants)
(8)
(6)
(3)
(3)
(6)
(6)
(6)
(12)
ΔH = 12 x –394 or – 4728 (3) + 6 x –286 or –1716 (3) – {2 x 49 or 98 (3) + 0}
-1
= – 6542 => ΔHc = – 3271 (3)
[Allow 3 marks only for + 3271 kJ mo ]
2006
Question 6
(a) The table shows the octane numbers of four hydrocarbons.
(i) What is meant by the octane number of a fuel?
(8)
(ii) Hexane has the lowest octane number of the four compounds listed.
What structural feature of the molecule contributes to this?
(3)
(iii) In the case of each of the other three compounds, identify the
structural feature of its molecules which contributes to it having a high
octane number.
(9)
(iv) Name the process carried out in an oil refinery that converts hexane
to compounds such as cyclohexane and benzene.
Why is the use of benzene in petrol strictly controlled?
(6)
(b) (i) Give two reasons why oxygenates such as MTBE are added to petrol. (ii) Give two reasons why the addition of
lead to petrol has been discontinued.
(12)
(c) The combustion of cyclohexane may be described by the following balanced equation:
C6H12(l) + 9O2(g) 6CO2(g) + 6H2O(l)
Given that the heats of formation of cyclohexane, carbon dioxide and water are –156, –394 and –286 kJ mol–1,
respectively, calculate the heat of combustion of cyclohexane. (12)
2006
(a)
Question 6
(i)
(ii)
(iii)
(iv)
(b)
(i)
(ii)
(c)
WHAT: measure of tendency to auto-ignite (knock) or number representing ability of fuel to
resist auto-igniting (knocking)
WHAT: straight chain / unbranched
IDENTIFY: cyclohexane: ring / cyclic
benzene: aromatic [Accept ring / cyclic]
2,2,4-trimethylpentane: branched
PROCESS: dehydrocyclisation
WHY: benzene is carcinogenic or benzene is toxic (poisonous)
GIVE: high octane rating (number) / reduces knocking
produce clean products / reduce pollution / more complete oxidation / less carbon monoxide
produced /do not poison catalyst in converter (2 × 3)
GIVE: it poisons (destroys) the catalyst in catalytic converter //
lead emission presents a health hazard / toxic (poisonous) to living things (2 × 3)
[Do not accept „lead is a pollutant‟ or „it damages the environment‟]
–1
– 3924 kJ mol (12)
ΔH = Σ ΔH
– Σ ΔH
f(products)
(8)
(3)
(3)
(3)
(3)
(3)
(3)
(6)
(6)
(12)
f(reactants)
ΔH = 6 × –394 or –2364 (3) + 6 × –286 or –1716 (3) – {1 × –156 or –156 (3) + 0}
=> ΔHc = – 3924 (3)
4. 2007
Question 6
Useful hydrocarbons are obtained by the fractional distillation of crude oil, which itself has little or no direct use.
Hydrocarbons are excellent fuels.
(a) In which fraction of crude oil do pentane and its isomers occur?
(5)
Give the systematic (IUPAC) name of each of the structural isomers of pentane shown below.
(9)
Which of these isomers would you predict to have the lowest octane number? Justify your choice in terms of the structural
features of the molecules.
(9)
Write a balanced equation for the combustion of pentane (C5H12) in excess oxygen.
(6)
(b) Naphtha and gas oil are two of the hydrocarbon fractions obtained from the fractional distillation of crude oil. How do
the molecules of the naphtha fraction differ from the molecules of the gas oil fraction?
(3)
Explain with the aid of a labelled diagram how naphtha (b.p. approximately 100 ºC) is separated from gas oil
(b.p. approximately 300 ºC) in the fractional distillation of crude oil.
(9)
Bitumen is a residue fraction obtained from crude oil. Give one use for bitumen.
(3)
(c) What is catalytic cracking? What is its economic importance in oil refining?
(6)
2007
(a)
(b)
(c)
Question 6
WHICH: light gasoline (petrol) [Accept “petroleum”]
[Allow “second highest fraction” or “from C5 to C10(C11)”]
GIVE: pentane // 2-methylbutane // 2,2-dimethylpropane (3 x 3)
[Numbers are not required as the structures are unambiguous but no marks should be awarded if
incorrect numbers are used]
WHICH: pentane or the one on the left
JUSTIFY: pentane is a straight (unbranched) chain molecule
[“longest chain” or “not highly branched” are not acceptable.]
WRITE: C5H12 + 8O2 → 5CO2 + 6H2O
FORMULAS: (3) BALANCING: (3)
HOW: naphtha (they) have shorter (smaller, less carbon atoms, smaller mass, lighter) chains /
gas oil have longer (bigger, more carbon atoms, bigger mass, heavier) chains
EXPL: diagram with one correct label (3)
[layers or outlets must be shown; outlets may be shown
by tubes (pipes), holes, gaps, lines, arrows (→)]
heat (boil) or pass vapour up tower (column) or temperature
gradient shown (3)
naphtha condenses higher up or gas oil comes off lower down (3)
GIVE: road surfacing / roofing / waterproofing (3)
WHAT: splitting (breaking) of long chain molecules by heat and catalyst(s)
[Accept “hydrocarbons” for “molecules”]
ECON: more demand for products / products used as feedstock for chemical industry / gives
higher octane numbers
(5)
(9)
(3)
(6)
(6)
(3)
(12)
(3)
(3)
2008 Question 6
(a) The hydrocarbon molecules in petrol typically contain carbon chains with between five and ten carbon atoms. The
most widely used petrol in Ireland has an octane number of 95.
(i) What is meant by the octane number of a fuel?
(5)
(ii) The two hydrocarbons used as references when establishing the octane number of a fuel are
heptane and 2,2,4-trimethylpentane. Draw the structure of each of these molecules.
(6)
(iii) Crude oil is separated into a number of fractions in oil refining. Name the two fractions which
contain molecules with the carbon chain lengths needed for petrol.
(6)
(iv) Dehydrocyclisation is one of the processes used to increase the octane numbers of hydrocarbons.
What two changes to the hydrocarbon molecules occur during this process?
(6)
(v) Ethanol is an example of an oxygenate. Give another example of an oxygenate.
Give two reasons why oxygenates are added to petrol.
(9)
5. (b) Write a balanced chemical equation for the combustion of ethanol, C2H5OH. Given that the heats of formation of
ethanol, carbon dioxide and water are –278, –394 and –286 kJ mol–1, respectively, calculate the heat of combustion of
ethanol.
(18)
2008
(a)
Question 6
(i)
(ii)
(iii)
(iv)
(v)
(b)
(c)
2008
WHAT: measure of tendency to auto-ignite (knock,) / number representing ability to resist autoignition (knocking, etc.) /
DRAW: heptane: CH3CH2CH2CH2CH2CH2CH3 / CH3(CH2)5CH3 /
(5)
NAME: light gasoline / petroleum (3) naphtha (3)
WHAT: removal (loss) of hydrogen [Accept “hydrogen produced”.] (3)
ring (aromatic, cyclic) formation (3)
EXAMPLE: methanol or methyl-t-butyl ether (MTBE) [Accept correct formula] (3)
GIVE: raise octane number / decrease knocking (3)
less pollution (CO) produced or more environmentally friendly or alternatives for lead (3)
[Accept “less harmful gases”, “less harmful to environment”, but not “less harmful”.]
WRITE: C2H5OH + 3O2 → 2CO2 + 3H2O
FORMULAS: (3) BALANCING (3)
–1
CALC: – 1368 kJ mol
ΔH = Σ ΔHf(products) – Σ ΔHf(reactants)
ΔH = 2 × – 394 or – 788 (3) + 3 × – 286 or – 858 (3) – {–278 (3) + 0}
ΔH = – 1368 (3)
(6)
(6)
(6)
(9)
(6)
(12)
Question 11 (a)
Alcohols can be obtained by the reduction of aldehydes and ketones using hydrogen and a suitable catalyst.
(i) Name a suitable catalyst for these reduction reactions.
(4)
(ii) Name the alcohol produced when propanal (C2H5CHO) is reduced.
(3)
(iii) Draw the structure of the alcohol produced when propanone (CH3COCH3) is reduced. To which class (primary,
secondary or tertiary) of alcohols does it belong?
(6)
(iv) Which of the two compounds, propanal or propanone, would be oxidised by warm Fehling’s solution?
Give the name and structure of the organic product of the oxidation reaction.
(9)
(v) Give one common use for propanone.
(3)
2008
(b)
Question 11
(i)
(ii)
(iv)
MASS: 1144 g (6)
143 x 8 = 1144 (6)
MOLES: 26 mol
1144 ÷ 44 (3) = 26 (3)
To be accepted as a slip, some work must be shown in these calculations.
VOLUME: 624 litres
26 x 24 (3) = 624 (3)
(6)
SUV: 528 litres
(6)
[Note: subtraction step (3); other step(s) (4)]
[In part (iii), using 22.4 for 24 loses the 3 (4) marks for that step but the candidate is penalised once
only. The same applies to the use of PV = nRT except in cases where the correct answer is obtained.]
(6)
(6)
6. 2009
Question 6
(a) Define (i) hydrocarbons, (ii) structural isomers.
(8)
(b) Give a use for the kerosene fraction obtained when crude oil is fractionated.
Explain why some of the kerosene produced in oil refining is subjected to catalytic cracking.
(9)
(c) Straight chain molecules of C13H28 occur in the kerosene fraction. Upon cracking a molecule of
C13H28, a C2H4 molecule, a C4H8 molecule and an unbranched alkane molecule are obtained.
Identify this unbranched alkane molecule and state its octane number.
Draw structures for three of the isomers of C4H8.
(15)
(d) Name two other processes carried out in oil refineries to modify hydrocarbon structures.
(6)
(e) The combustion of one of the C4H8 isomers is described by the following balanced equation.
C4H8 + 6O2 4CO2 + 4H2O
ΔH = –2710 kJ mol–1
The standard heats of formation of water and carbon dioxide are –286 and –394 kJ mol–1, respectively.
Calculate the heat of formation of this C4H8 isomer.
(12)
2009
(a)
Question 6
(i)
(ii)
(b)
(c)
(d)
(e)
compounds of* carbon (C) and hydrogen (H) only (4)
[*if “containing” is used, then “only” has to accompany it]
(ii) compounds with same molecular* formula but different structural formulas ([*not „chemical‟] (4)
GIVE: home heating / used as paraffin oil / jet (aviation, aircraft) fuel / bus fuel / rocket fuel /
storing reactive elements (metals e.g. alkali metals; non-metals e.g. white phosphorus) /
solvent / lubricant / lighting /(paraffin lamps) / cooking / produce petrol (gasoline) / camping
stoves [Note: medicinal liquid paraffin and paraffin wax (candles) are not kerosene derivatives.]
EXPLAIN: greater demand for shorter chains (smaller molecules, kerosene chains too long) //
useful products // lighter fractions // increased octane number // production of raw materials
(alkenes – or named alkene, monomers) for making polymers (plastics, petrochemicals) (6 + 3)
[The first correct point from GIVE or EXPLAIN gets (6)].
IDENTIFY: heptane or C7H16 or CH3(CH2)5CH3 (3)
STATE: octane number: zero) [IDENTIFY & STATE are linked] (3)
NAME: isomerisation // reforming (dehydrocyclisation) (2 x 3)
–1
CALCULATE: – 10 kJ mol (12)
–1
C4H8 + 6O2 = 4CO2 + 4H2O
ΔH = – 2710 kJ mol
ΔH(reaction) = ΔHf (products) – ΔHf (reactants)
– 2710 = 4 x –394 or –1576 + 4 x –286 or –1144 – ΔHf(compound) *
ΔHf(compound) = 4 x –394 or –1576 (3) + 4 x –286 or–1144 (3) + 2710** (3)
–1
= – 10 kJ mol (3)
*Give 3 for – 2710 only if the full equation in this line is given correctly
(8)
(9)
(15)
(6)
(12)