1. Joseph Proust, a French scientist, discovered the Law of Constant Proportions through experiments on chemical reactions forming compounds. He found that the mass ratios of elements in a compound are always fixed, regardless of preparation method.
2. Experiments reacting copper and sulfur in different ratios showed that the average mass ratio of Cu to S was 2:1. Calculations determining the molar ratios also gave a ratio of 1:1, confirming the law.
3. Further experiments and calculations on copper(II) oxide supported that its composition follows the law, with the molar ratio of Cu to O always being 1:1.
1. The document discusses properties of elements in the periodic table, including atomic radius, ionic radius, classification of metals, nonmetals, and metalloids.
2. Atomic radius decreases from left to right within a period and increases down a group as the principal quantum level increases. Ionic radius is measured from the distance between nuclei of bonded ions. The ionic radius of cations decreases as the charge increases, while that of anions increases as the charge increases.
3. Elements are classified based on properties as metals, nonmetals, metalloids, and transition metals. Metals are good conductors of heat and electricity while nonmetals are typically poor conductors.
John Dalton was an English chemist and meteorologist who is best known for introducing the atomic theory. He proposed that all matter is composed of small indivisible particles called atoms. Dalton's atomic theory marked the beginning of the modern atomic model in science and greatly aided the development of chemistry. He also discovered Dalton's law of partial pressures, which states that the total pressure of a gas mixture is equal to the sum of the partial pressures of the individual gas components.
The document contains examples and explanations of concepts related to chemistry calculations including:
- Percentage composition problems calculating the percent by mass of elements in compounds.
- Empirical formula problems finding the lowest whole number ratio of atoms in a compound from percentage or mole composition data.
- Molecular formula problems relating the empirical formula to molar mass to determine the actual formula.
- Hydrate problems using the formula for hydrated compounds to determine the amount of water bonded in the crystal structure from percentage or mass composition data.
Percent Composition, Empirical and Molecular FormulaEllebasy Tranna
This document provides examples and explanations for calculating percent composition, empirical formulas, and molecular formulas. It begins with examples of calculating percent composition of elements in compounds and mixtures. It then defines empirical and molecular formulas, and provides steps for calculating empirical formulas from mass percentages of elements or experimental data. Several examples are worked through. The document emphasizes that empirical formulas show the simplest whole number ratio of elements in a compound, while molecular formulas indicate the actual number of each type of atom in a molecule.
1. The document discusses properties of elements in the periodic table, including atomic radius, ionic radius, classification of metals, nonmetals, and metalloids.
2. Atomic radius decreases from left to right within a period and increases down a group as the principal quantum level increases. Ionic radius is measured from the distance between nuclei of bonded ions. The ionic radius of cations decreases as the charge increases, while that of anions increases as the charge increases.
3. Elements are classified based on properties as metals, nonmetals, metalloids, and transition metals. Metals are good conductors of heat and electricity while nonmetals are typically poor conductors.
John Dalton was an English chemist and meteorologist who is best known for introducing the atomic theory. He proposed that all matter is composed of small indivisible particles called atoms. Dalton's atomic theory marked the beginning of the modern atomic model in science and greatly aided the development of chemistry. He also discovered Dalton's law of partial pressures, which states that the total pressure of a gas mixture is equal to the sum of the partial pressures of the individual gas components.
The document contains examples and explanations of concepts related to chemistry calculations including:
- Percentage composition problems calculating the percent by mass of elements in compounds.
- Empirical formula problems finding the lowest whole number ratio of atoms in a compound from percentage or mole composition data.
- Molecular formula problems relating the empirical formula to molar mass to determine the actual formula.
- Hydrate problems using the formula for hydrated compounds to determine the amount of water bonded in the crystal structure from percentage or mass composition data.
Percent Composition, Empirical and Molecular FormulaEllebasy Tranna
This document provides examples and explanations for calculating percent composition, empirical formulas, and molecular formulas. It begins with examples of calculating percent composition of elements in compounds and mixtures. It then defines empirical and molecular formulas, and provides steps for calculating empirical formulas from mass percentages of elements or experimental data. Several examples are worked through. The document emphasizes that empirical formulas show the simplest whole number ratio of elements in a compound, while molecular formulas indicate the actual number of each type of atom in a molecule.
This document provides information about the mole concept in chemistry. It defines the mole as the amount of substance that contains as many elementary entities as there are atoms in 12 grams of carbon-12. It then discusses how to calculate the number of moles, mass of one mole of atoms or molecules, and molar mass. The document also explains how to derive empirical and molecular formulas from percentage composition data and relative molecular masses. It provides examples of calculating limiting reactants and the molar volume of gases.
This document discusses the mole concept in chemistry. It defines the mole as the amount of substance containing 6.02x1023 particles. A mole of any substance has a mass in grams equal to its molar mass. The document explains how to determine empirical and molecular formulas from percentage composition data using mole calculations. It also discusses limiting reactants and using moles to calculate gas volumes based on Avogadro's Law. Several examples are provided to demonstrate determining formulas from mass or molar mass data.
This document provides an overview of key concepts related to the mole concept in chemistry. It defines the mole as the number of atoms or molecules in 1 gram of hydrogen or 12 grams of carbon. The mole concept allows chemists to relate mass, number of particles, and volume of gases. It discusses how to calculate empirical and molecular formulas, Avogadro's constant, molar mass, limiting reactants, and other mole-related calculations and applications. Worked examples are provided to demonstrate how to use the mole concept to find formulas of compounds from percentage composition data and other information.
Stoichiometry deals with the numerical relationships between elements and compounds in chemical reactions. It involves calculating the masses of reactants and products using moles, molar mass, molecular mass, and Avogadro's number. Percentage composition is the percentage by mass of each element in a compound. Understanding moles, molar mass, and balancing chemical equations allows solving stoichiometry problems involving mass relationships in chemical reactions.
2011 topic 01 lecture 2 - empirical and molecular formulaeDavid Young
The document discusses empirical and molecular formulas. It provides examples to show how to determine the empirical formula from percent composition data and how to then determine the molecular formula from the empirical formula and molar mass. Specifically, it shows how to calculate the empirical formula of adipic acid is C3H5O2 from its percent composition by mass. It then shows that if the molar mass of adipic acid is 146 g/mol, and the molar mass of C3H5O2 is 73.08 g/mol, then the molecular formula of adipic acid must be C6H10O4.
This document provides steps for calculating empirical and molecular formulas from percent composition data and molar mass. It presents an example calculation showing that a compound that is 43.7% P and 56.3% O with a molar mass of 283.88 g/mol has an empirical formula of P2O5 and a molecular formula of P4O10. Several practice problems are provided for students to determine empirical and molecular formulas.
This document discusses concepts related to stoichiometry including empirical formulas, molecular formulas, percentage composition, and hydrates. It provides examples of calculating empirical formulas from mass percentages of elements in compounds and using mole ratios. It also distinguishes between empirical formulas that give the lowest whole number ratio of atoms in a compound and molecular formulas that give the actual ratio in compounds.
Chapter 7.4 : Determining Chemical FormulasChris Foltz
This document discusses determining chemical formulas, including:
1) Defining empirical and molecular formulas, and how to calculate empirical formulas from percentage or mass composition data.
2) Explaining how to determine a molecular formula from an empirical formula using the relationship between molecular formula mass and empirical formula mass.
3) Providing examples of calculating empirical formulas from composition data and determining molecular formulas from empirical formulas and molar masses.
Stoichiometry deals with the numerical relationships of elements and compounds and the mathematical proportions of reactants and products in chemical transformations
This chapter discusses the mole concept, including defining the mole, deriving empirical and molecular formulas, stating Avogadro's Law, and applying the mole concept to ionic and molecular equations. It introduces the mole as the amount of substance containing 6x1023 particles. It provides examples of how to determine the empirical formula, molecular formula, and formula of a compound from composition data. It also discusses molar volume of gases and limiting reactants. Worked examples are included for many of these concepts.
The document discusses how to determine the formula of a compound through experimentation. It provides an example of finding the formula of magnesium oxide. Key steps include measuring the masses of reactants and products, calculating moles of each substance, and determining the ratio of elements in the compound based on the mole ratios. The formula of magnesium oxide in this example is MgO.
The document contains 6 chemistry problems asking for empirical and molecular formulas of compounds given their percentage compositions or products of combustion. Problem 1 asks for the empirical formula of a compound containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen. Problem 2 asks for the molecular formula if the molar mass is 110 g/mol. Problem 3 asks for the empirical formula of a compound containing 18.7% lithium, 16.3% carbon, and 65.0% oxygen. Problem 4 asks for the molecular formula if the molar mass is 73.8 g/mol. Problems 5 and 6 similarly ask for the empirical and molecular formulas of acetic acid and aniline given combustion products and m
The empirical formula provides the simplest whole number ratio of elements in a compound. It is determined through experimentation involving measuring mass of elements before and after a reaction. The molecular formula indicates the actual number of each type of atom in a molecule of the compound and can be determined from comparing the empirical formula mass to the measured molecular mass. The percentage composition by mass of each element in a compound can be calculated from the empirical formula. Structural formulas depict the specific arrangement of atoms in a molecule.
The document discusses chemical formulae including molecular, empirical and structural formulae. It provides examples of formulae for different types of compounds such as ionic compounds, molecular compounds and covalent compounds. It also gives examples of how to calculate empirical formulae from experimental data including mass of elements and relative atomic masses.
Qualitative and Quantitative Analysis, Empirical and Molecular FormulaFawad Mueen Arbi
This document discusses qualitative and quantitative analysis, empirical and molecular formulas, and combustion analysis. It provides details on:
- The differences between qualitative analysis, which identifies substances, and quantitative analysis, which determines amounts.
- How empirical formulas represent the simplest whole number ratio of elements in a compound and molecular formulas use actual atom counts.
- The process of combustion analysis, where a compound is burned and the products analyzed to determine the empirical formula based on the amounts of carbon dioxide and water produced.
The document provides information about chemical formulas and equations. It defines empirical and molecular formulas, and explains how to determine them through calculation of moles and mass ratios of elements in a compound. It also describes writing and balancing chemical equations, naming ionic compounds based on their constituent ions, and using formulas and equations to solve stoichiometric problems. Key topics covered include determining formulas from experimental data, relating formulas to molecular structure and mass, and representing chemical reactions systematically.
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...indexPub
The recent surge in pro-Palestine student activism has prompted significant responses from universities, ranging from negotiations and divestment commitments to increased transparency about investments in companies supporting the war on Gaza. This activism has led to the cessation of student encampments but also highlighted the substantial sacrifices made by students, including academic disruptions and personal risks. The primary drivers of these protests are poor university administration, lack of transparency, and inadequate communication between officials and students. This study examines the profound emotional, psychological, and professional impacts on students engaged in pro-Palestine protests, focusing on Generation Z's (Gen-Z) activism dynamics. This paper explores the significant sacrifices made by these students and even the professors supporting the pro-Palestine movement, with a focus on recent global movements. Through an in-depth analysis of printed and electronic media, the study examines the impacts of these sacrifices on the academic and personal lives of those involved. The paper highlights examples from various universities, demonstrating student activism's long-term and short-term effects, including disciplinary actions, social backlash, and career implications. The researchers also explore the broader implications of student sacrifices. The findings reveal that these sacrifices are driven by a profound commitment to justice and human rights, and are influenced by the increasing availability of information, peer interactions, and personal convictions. The study also discusses the broader implications of this activism, comparing it to historical precedents and assessing its potential to influence policy and public opinion. The emotional and psychological toll on student activists is significant, but their sense of purpose and community support mitigates some of these challenges. However, the researchers call for acknowledging the broader Impact of these sacrifices on the future global movement of FreePalestine.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
How to Download & Install Module From the Odoo App Store in Odoo 17Celine George
Custom modules offer the flexibility to extend Odoo's capabilities, address unique requirements, and optimize workflows to align seamlessly with your organization's processes. By leveraging custom modules, businesses can unlock greater efficiency, productivity, and innovation, empowering them to stay competitive in today's dynamic market landscape. In this tutorial, we'll guide you step by step on how to easily download and install modules from the Odoo App Store.
Gender and Mental Health - Counselling and Family Therapy Applications and In...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
9. 9
บทที่ 4 โมลและสูตรเคมี
4.4 สูตรเคมี : ร้อยละโดยมวลของธาตุ
ร้อยละโดยมวลของธาตุA ในสารประกอบ =
มวลของธาตุA
มวลของสารประกอบ
x 100
ตัวอย่างโจทย์ 1. จงคานวณมวลเป
็ นร้อยละของ Fe ใน Fe2O3
ร้อยละโดยมวลของธาตุFe =
𝟐𝒙𝟓𝟔
𝟏𝟔𝟎
x 100 = 70% g Fe
1
2
ใน Fe2O3 160 g มี Fe 112 g
ถ้า Fe2O3 100 g มี Fe 100 g x
112 g
160 g
= 70% g Fe
มวลโมเลกุล Fe2O3 = (56x2) + (16x3) = 160
10. 10
บทที่ 4 โมลและสูตรเคมี
4.4 สูตรเคมี : กฎสัดส่วนคงที่
4.4 สูตรเคมี : ร้อยละโดยมวลของธาตุ
ตัวอย่างโจทย์ 2. กรดแลกติกเป
็ นองค์ประกอบในนมเปรี้ยว มีสูตรโมเลกุล คือ C3H6O3
จงคานวณหามวลของคาร์บอนในกรดแลกติกจานวน 50.0 กรัม
มวล C = 50 g C3H6O3 𝐱
𝟑 𝐱 𝟏𝟐 𝐠 𝐂
𝟗𝟎 g C3H6O3
= 20 g C
1
2
กรดแลกติก C3H6O3 𝟗𝟎 g มี คาร์บอน 𝟑𝟔 𝐠
กรดแลกติก C3H6O3 𝟓𝟎 g มี คาร์บอน
50 g x 36 g
90 g
= 20 g C
มวลโมเลกุล C3H6O3 = (12x3) + 6 + (16x3) = 90
11. 11
บทที่ 4 โมลและสูตรเคมี
4.4 สูตรเคมี : กฎสัดส่วนคงที่
4.4 สูตรเคมี : ร้อยละโดยมวลของธาตุ
ตัวอย่างโจทย์ 3. สารตัวอย่าง 0.500 กรัม ประกอบด้วยธาตุคาร์บอน (C) ไฮโดรเจน (H)
และออกซิเจน (O) เมื่อเผาไหม้อย่างสมบรูณ์ พบว่าเกิดแก๊สคาร์บอนไดออกไซด์ (CO2) 0.687
กรัม และไอน้า (H2O) 0.140 กรัม จงคานวณร้อยละโดยมวลของคาร์บอน ไฮโดรเจน และ
ออกซิเจนในสาร ตัวอย่าง
หามวล C ใน คาร์บอนไดออกไซด์ (CO2) 0.687 กรัม
1
มวล C = 0.687 g CO2 𝐱
𝟏𝟐 𝐠 𝐂
𝟒𝟒 𝐠 CO2
= 0.187 g C
ร้อยละโดยมวลของธาตุC =
𝟎.𝟏𝟖𝟕
𝟎.𝟓𝟎𝟎
x 100%
= 37.4 % C
12. 12
บทที่ 4 โมลและสูตรเคมี
4.4 สูตรเคมี : กฎสัดส่วนคงที่
4.4 สูตรเคมี : ร้อยละโดยมวลของธาตุ
ตัวอย่างโจทย์ 3. สารตัวอย่าง 0.500 กรัม ประกอบด้วยธาตุคาร์บอน (C) ไฮโดรเจน (H) และ
ออกซิเจน (O) เมื่อเผาไหม้อย่างสมบรูณ์ พบว่าเกิดแก๊สคาร์บอนไดออกไซด์ (CO2) 0.687 กรัม
และไอน้า (H2O) 0.140 กรัม จงคานวณร้อยละโดยมวลของคาร์บอน ไฮโดรเจน และออกซิเจน
ในสาร ตัวอย่าง
หามวล H ใน ไอน้า (H2O) 0.140 g
2
มวล H = 0.140 g H2O 𝐱
𝟐 𝐠 𝐇
𝟏𝟖 𝐠 H2O
= 0.0156 g H
ร้อยละโดยมวลของธาตุH =
𝟎.𝟎𝟏𝟓𝟔
𝟎.𝟓𝟎𝟎
x 100%
= 3.12 % H