AQA GCSE Chemistry My Revision Notes
... (2 marks) (f) Another way of softening hard water is to use sodium carbonate. Explain how and include a chemical equation in your answer. (4 marks) Water of the correct quality is essential for life. In the UK water drawn from rivers or reservoirs is treated before being pumped into homes. (g) Expla ...
... (2 marks) (f) Another way of softening hard water is to use sodium carbonate. Explain how and include a chemical equation in your answer. (4 marks) Water of the correct quality is essential for life. In the UK water drawn from rivers or reservoirs is treated before being pumped into homes. (g) Expla ...
Chapter 2 - Portal UniMAP
... • Process streams consist of mixtures of liquids or gases, or solutions of one or more solutes in a liquid solvents. • The following terms may be used to define the composition of a mixture of substances, including a species A. • Mass fraction: xA= mass of A / total mass Unit: kg A/kg total; g A/g ...
... • Process streams consist of mixtures of liquids or gases, or solutions of one or more solutes in a liquid solvents. • The following terms may be used to define the composition of a mixture of substances, including a species A. • Mass fraction: xA= mass of A / total mass Unit: kg A/kg total; g A/g ...
13AP General Equilibrium FR worksheet (missing 1988)
... (b) What change, if any, will occur in G° for the reaction as the temperature is increased. Explain your reasoning in terms of thermodynamic principles. (c) If He gas is added to the original reaction mixture at constant volume and temperature, what will happen to the partial pressure of Cl2? Expla ...
... (b) What change, if any, will occur in G° for the reaction as the temperature is increased. Explain your reasoning in terms of thermodynamic principles. (c) If He gas is added to the original reaction mixture at constant volume and temperature, what will happen to the partial pressure of Cl2? Expla ...
Unit 1: Sig. Figs, Compounds, Elements, Homo/Hetero mixtures
... 1. Which of the following gases does not exist in nature as a diatomic molecule? a. Nitrogen b. Helium c. Hydrogen d. oxygen 2. Ionic compounds generally form: a. Liquids b. Gases c. Crystals d. molecules 3. In metallic bonding, the valence electrons of all atoms are shared in: a. A nonpolar covalen ...
... 1. Which of the following gases does not exist in nature as a diatomic molecule? a. Nitrogen b. Helium c. Hydrogen d. oxygen 2. Ionic compounds generally form: a. Liquids b. Gases c. Crystals d. molecules 3. In metallic bonding, the valence electrons of all atoms are shared in: a. A nonpolar covalen ...
advanced chemistry may 2011 marking scheme
... Award 1 mark for correct representation of reactants and products showing products starting from zero concn and remaining below concentration of reactants and 1 mark for correct point when equilibrium is reached. Deduct 1 mark if equilibrium concentrations are shown as being equal. (d) The reaction ...
... Award 1 mark for correct representation of reactants and products showing products starting from zero concn and remaining below concentration of reactants and 1 mark for correct point when equilibrium is reached. Deduct 1 mark if equilibrium concentrations are shown as being equal. (d) The reaction ...
Chapter 3 Note Packet
... of the same elements in the same proportion by mass, no matter how large or small the sample. Example: Water is always composed of 2 Hydrogen to 1 Oxygen ...
... of the same elements in the same proportion by mass, no matter how large or small the sample. Example: Water is always composed of 2 Hydrogen to 1 Oxygen ...
Redox Introduction
... In burning, oxygen unites rapidly with carbon to form CO2. Observation of these reactions gave rise to the terms "slow" and "rapid" oxidation. Chemists recognize, however, that other nonmetallic elements unite with substances in a manner similar to that of oxygen. – Hydrogen, antimony, and sodium al ...
... In burning, oxygen unites rapidly with carbon to form CO2. Observation of these reactions gave rise to the terms "slow" and "rapid" oxidation. Chemists recognize, however, that other nonmetallic elements unite with substances in a manner similar to that of oxygen. – Hydrogen, antimony, and sodium al ...
CHEM 1411 – STUDY-GUIDE-for-TEST-2
... 56. During volcanic eruptions, hydrogen sulfide gas is given off and oxidized by air according to the following chemical equation: 2H2S(g) + 3O2(g) 2SO2(g) + 2H2O(g) Calculate the standard enthalpy change for the above reaction given: 3S(s) + 2H2O(g) 2H2S(g) + SO2(g) H° = 146.9 kJ/mol S(s) + O2 ...
... 56. During volcanic eruptions, hydrogen sulfide gas is given off and oxidized by air according to the following chemical equation: 2H2S(g) + 3O2(g) 2SO2(g) + 2H2O(g) Calculate the standard enthalpy change for the above reaction given: 3S(s) + 2H2O(g) 2H2S(g) + SO2(g) H° = 146.9 kJ/mol S(s) + O2 ...
General and Organic Chemistry Review Primer
... chemist John Dalton, is defined as one twelfth of the mass of an atom of carbon-12. Because the isotopes of an element do not occur with equal frequency, the average atomic mass unit (the weighted average of the atomic masses of the naturally occurring isotopes) is used. For example, hydrogen has th ...
... chemist John Dalton, is defined as one twelfth of the mass of an atom of carbon-12. Because the isotopes of an element do not occur with equal frequency, the average atomic mass unit (the weighted average of the atomic masses of the naturally occurring isotopes) is used. For example, hydrogen has th ...
Chemistry
... ionic and molecular equation. Mass fraction of solute in a solution. The structure of the water molecule; hydrogen bonding in water. The color of indicators (universal litmus, phenolphthalein, methylorange) in acidic, alkaline and neutral medium. Ion exchange reactions between the electrolytes in th ...
... ionic and molecular equation. Mass fraction of solute in a solution. The structure of the water molecule; hydrogen bonding in water. The color of indicators (universal litmus, phenolphthalein, methylorange) in acidic, alkaline and neutral medium. Ion exchange reactions between the electrolytes in th ...
CHAPTER 17
... where, Po is the ordinary vapor pressure of the liquid P is the vapor pressure when liquid is present in droplets. M is molar mass (See Table 18.2) ...
... where, Po is the ordinary vapor pressure of the liquid P is the vapor pressure when liquid is present in droplets. M is molar mass (See Table 18.2) ...
preliminary course outline facilitators course description
... solving quadratic equations, knowledge of logarithms and basic calculus will also be necessary. The course is structured around Chapters 13-18 of the course text in which we examine how and why chemical reactions occur. In Chapter 13 we examine how quickly chemical reactions occur, and how catalysts ...
... solving quadratic equations, knowledge of logarithms and basic calculus will also be necessary. The course is structured around Chapters 13-18 of the course text in which we examine how and why chemical reactions occur. In Chapter 13 we examine how quickly chemical reactions occur, and how catalysts ...
Chemistry Spell check on
... The questions for Section 1 are contained in the question paper X713/76/02. Read these and record your answers on the answer grid on Page 03 opposite. Use blue or black ink. Do NOT use gel pens or pencil. 1. The answer to each question is either A, B, C or D. Decide what your answer is, then fill ...
... The questions for Section 1 are contained in the question paper X713/76/02. Read these and record your answers on the answer grid on Page 03 opposite. Use blue or black ink. Do NOT use gel pens or pencil. 1. The answer to each question is either A, B, C or D. Decide what your answer is, then fill ...
The mole and calculations
... Another type of chemical reaction to be aware of is the combustion reaction. Combustion is used to measure the amount of hydrogen and carbon in an organic substance as it burns in the presence of oxygen. All of the hydrogen is converted or H2O, while all of the carbon is converted to CO2. If the ...
... Another type of chemical reaction to be aware of is the combustion reaction. Combustion is used to measure the amount of hydrogen and carbon in an organic substance as it burns in the presence of oxygen. All of the hydrogen is converted or H2O, while all of the carbon is converted to CO2. If the ...
Problem 14. MAGNESIUM DETERMINATION
... The natural tendency of any chemical reaction to proceed in a certain direction at constant temperature and pressure is determined by the sign of the Gibbs energy of the reaction, G. This is the universal principle. If G < 0, the reaction can proceed predominantly in the forward direction (a produ ...
... The natural tendency of any chemical reaction to proceed in a certain direction at constant temperature and pressure is determined by the sign of the Gibbs energy of the reaction, G. This is the universal principle. If G < 0, the reaction can proceed predominantly in the forward direction (a produ ...
Sample Exercise 19.1 Identifying Spontaneous Processes
... Plan: In part (a) we can make this prediction by determining the sign of ΔS° for the reaction and then using that information to analyze Equation 19.12. In part (b) we need to calculate ΔH° and ΔS° for the reaction by using the data in Appendix C. We can then use Equation 19.12 to calculate ΔG°. Sol ...
... Plan: In part (a) we can make this prediction by determining the sign of ΔS° for the reaction and then using that information to analyze Equation 19.12. In part (b) we need to calculate ΔH° and ΔS° for the reaction by using the data in Appendix C. We can then use Equation 19.12 to calculate ΔG°. Sol ...
Document
... Plan: We first need to write the chemical formulas of the reactants and products and to determine which product is insoluble. Then we write and balance the molecular equation. Next, we write each soluble strong electrolyte as separated ions to obtain the complete ionic equation. Finally, we eliminat ...
... Plan: We first need to write the chemical formulas of the reactants and products and to determine which product is insoluble. Then we write and balance the molecular equation. Next, we write each soluble strong electrolyte as separated ions to obtain the complete ionic equation. Finally, we eliminat ...
SAMPLE EXERCISE 4.5 Comparing Acid Strengths
... Plan: We first need to write the chemical formulas of the reactants and products and to determine which product is insoluble. Then we write and balance the molecular equation. Next, we write each soluble strong electrolyte as separated ions to obtain the complete ionic equation. Finally, we eliminat ...
... Plan: We first need to write the chemical formulas of the reactants and products and to determine which product is insoluble. Then we write and balance the molecular equation. Next, we write each soluble strong electrolyte as separated ions to obtain the complete ionic equation. Finally, we eliminat ...
Stoichiometry
Stoichiometry /ˌstɔɪkiˈɒmɨtri/ is the calculation of relative quantities of reactants and products in chemical reactions.Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equals the total mass of the products leading to the insight that the relations among quantities of reactants and products typically form a ratio of positive integers. This means that if the amounts of the separate reactants are known, then the amount of the product can be calculated. Conversely, if one reactant has a known quantity and the quantity of product can be empirically determined, then the amount of the other reactants can also be calculated.As seen in the image to the right, where the balanced equation is:CH4 + 2 O2 → CO2 + 2 H2O.Here, one molecule of methane reacts with two molecules of oxygen gas to yield one molecule of carbon dioxide and two molecules of water. Stoichiometry measures these quantitative relationships, and is used to determine the amount of products/reactants that are produced/needed in a given reaction. Describing the quantitative relationships among substances as they participate in chemical reactions is known as reaction stoichiometry. In the example above, reaction stoichiometry measures the relationship between the methane and oxygen as they react to form carbon dioxide and water.Because of the well known relationship of moles to atomic weights, the ratios that are arrived at by stoichiometry can be used to determine quantities by weight in a reaction described by a balanced equation. This is called composition stoichiometry.Gas stoichiometry deals with reactions involving gases, where the gases are at a known temperature, pressure, and volume and can be assumed to be ideal gases. For gases, the volume ratio is ideally the same by the ideal gas law, but the mass ratio of a single reaction has to be calculated from the molecular masses of the reactants and products. In practice, due to the existence of isotopes, molar masses are used instead when calculating the mass ratio.