This document summarizes key concepts from Chapter 3 of a general chemistry textbook, including:
- Molecular and ionic compounds are composed of molecules and ions respectively. Ionic compounds form when atoms gain or lose electrons to become ions.
- The molecular mass and empirical formula of compounds can be determined from the relative abundances of elements in the compound.
- Common polyatomic ions and functional groups are important for naming organic and inorganic compounds systematically. Isomers have the same molecular formula but different structural arrangements.
OXIDATION OF POLYETHYLENE GLYCOL-200 BY POTASSIUM PERIODATE IN ALKALINE MEDIU...Ratnakaram Venkata Nadh
Kinetics of PEG-200 oxidation by potassium periodatewas studied in alkaline medium. First-order dependence of
reaction on periodate was observed. Rate of the reaction was found to be independent of substrate concentration.
An inverse fractional order with respect to alkaliwas shown. Arrhenius parameters were calculated. Rate law was
postulated taking into consideration of experimental results.
OXIDATION OF POLYETHYLENE GLYCOL-200 BY POTASSIUM PERIODATE IN ALKALINE MEDIU...Ratnakaram Venkata Nadh
Kinetics of PEG-200 oxidation by potassium periodatewas studied in alkaline medium. First-order dependence of
reaction on periodate was observed. Rate of the reaction was found to be independent of substrate concentration.
An inverse fractional order with respect to alkaliwas shown. Arrhenius parameters were calculated. Rate law was
postulated taking into consideration of experimental results.
In the realm of science, the study of atoms and molecules serves as the fundamental building block for understanding the nature of matter. Class 9 science introduces students to this fascinating world, unraveling the mysteries that lie within the microscopic realm. Let's delve into the basic concepts of atoms and molecules and explore how they form the basis of chemistry.
1. Introduction to Atoms and Molecules:
- Atoms are the basic building blocks of matter, consisting of a nucleus containing protons and neutrons, surrounded by electrons.
- Molecules are formed when atoms combine chemically. They can be elements (e.g., O2) or compounds (e.g., H2O).
2. Atomic Structure:
- Protons: Positively charged particles found in the nucleus, with a relative mass of 1.
- Neutrons: Neutral particles found in the nucleus, with a relative mass of 1.
- Electrons: Negatively charged particles orbiting the nucleus in shells, with a negligible mass compared to protons and neutrons.
3. Atomic Number and Mass Number:
- Atomic number (Z) represents the number of protons in an atom's nucleus.
- Mass number (A) represents the total number of protons and neutrons in an atom's nucleus.
4. Isotopes:
- Isotopes are atoms of the same element with different numbers of neutrons. They have the same atomic number but different mass numbers.
- Example: Hydrogen has three isotopes - protium (1H), deuterium (2H), and tritium (3H).
5. Molecules:
- Molecules are formed when atoms of different elements combine chemically in fixed ratios.
- The smallest unit of a compound that retains its chemical properties is a molecule.
- Example: Water (H2O) consists of two hydrogen atoms and one oxygen atom bonded together.
6. Chemical Formula:
- A chemical formula represents the types and numbers of atoms in a molecule.
- The subscript indicates the number of atoms of each element in the molecule.
- Example: The chemical formula for carbon dioxide is CO2.
7. Valency:
- Valency is the combining capacity of an element, determined by the number of electrons it needs to gain, lose, or share to achieve a stable configuration.
- It is represented by a positive or negative sign indicating the number of electrons gained or lost.
- Example: Sodium (Na) has a valency of +1, while chlorine (Cl) has a valency of -1.
8. Atomic Mass Unit (AMU):
An atomic mass unit is a unit of mass used to express atomic and molecular weights.
- It is defined as one-twelfth of the mass of a carbon-12 atom.
Understanding atoms and molecules is crucial for comprehending the behaviour of matter and chemical reactions in various fields of science, including chemistry and physics.
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The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Chemical formula – relative numbers of atoms of each element present
Empirical formula – the simplest whole number formula
Structural formula – the order and type of attachements
– shows multiple bonds
- may show lone pairs
- hard to show 3-d
Positive and negaive ions joined together by electrostatic forces
Metals tend to lose electrons to form cations
Non-metals tend to gain electrons to form anions
Ionic solids formulae are reported as the formula unit – inappropriate to call it a molecular formula
Na loses one electron to form the sodium ion
Cl gains one electron to form the chloride ion
Centers of ions are shown in the ball and stick model for clarity
Space filling model shows how the ions are actually in contact with one another.
We will discuss face centered cubic and other types of packing in chapter 13
Some inorganic compounds for molecules
Sulfur and phosporous for example.
They come in various forms called allotropes – these are one allotrope of each
Glucose
Emprical formula leads us to the name “carbohydrate”
Molecular formula tells us there are TWO moles of C per mole of halothane.
We also know about the MASSES of the compound and its elemental components.
Therefore we can talk about PERCENT COMPOSITION BY MASS
These types of calculations can be carried out in reverse for the following reasons:
Unknown compounds are analyzed for % composition.
Relative proportion of elements present on a mass basis.
Chemical formula requires mole basis, I.e. numbers of atoms.
If you know the molecular wt it is beneficial to choose that number, then only first three steps are required.
Read the problem carefully
Pick out the critical information
Think
Follow the steps to solve the problem
Step 5. You can multiply the rounded off one if you wish, but be careful of introducing an error
If all the subscripts are within ±0.1 you are probably OK to round to the integer.
Step 6: Simple multiplication is obvious here.
Water vapour absorbed by magnesium perchlorate
Carbon dioxide absorbed by sodium hydroxide.
The differences in mass of the absorbers before and after yiled the masses of water and CO2 produced in the reaction
Combustion takes place in an excess of oxygen so you cannot measure oxygen. Oxygen CAN be analyzed separately but is usually determined by difference.
Metals are electron sources
Non-metals are electron sinks
Sodium goes to the +1 oxidation state
Chlorine goes tot eh –1 oxidation state
Rule 1 states OS of elements is 0
Rule 2 the total OS is 0, Rule 6 oxygen should be –2 to give a total of –6 for O, therefore 2 Al must be +6 or each Al is +3.
Rule 2 the total OS is –1, Rule 6 oxygen should be –2 to give a total of –8 for O, therefore Mn must be +7.
Rule 2 the total OS is –1, Rule 3 beats Rule 5, so Na OS = +1 and H OS = -1.
There are other examples in the text and much more detail on the rules. Read this material carefully.
Trivial names such as water, ammonia, sugar, acetone, ether.
Write the unmodified name of the metal
Then write the name of the nonmetal, modifed to end in ide.
Ionic compounds must be electrically neutral
We have already discussed simple anions such as hydride, fluoride, chloride, iodide etc.
Most oxoacids are ternary compounds composed of hydrogen, oxygen and one other nonmental.
Oxoacids are molecular compounds, salts are ionic compounds
Ic and ate names are assigned to compounds (rather than ite and ate as in the oxoanions) in which the central nonmetal atom has an oxidation state equal to the periodic group number – 10
For halogens ic and ate names are assigned to compounds in which the halogen has an oxidation state of +5.
These are structural isomers. The structures are different
these molecules do not have the same formula, they are different
c) Now these molecules have the same formula and ALSO the same connectivity. These are geometric isomers.