Problem 5a
Glycine, an amino acid used by organisms to make proteins, is represented by the following molecular model. (a) Write its molecular formula.
Problem 5c
Glycine, an amino acid used by organisms to make proteins, is represented by the following molecular model. (c) Calculate how many moles of glycine are in a 100.0-g sample of glycine.
Problem 5d
Glycine, an amino acid used by organisms to make proteins, is represented by the following molecular model. (d) Calculate the percent nitrogen by mass in glycine.
Problem 6a
The following diagram represents a high-temperature reaction between CH4 and H2O. Based on this reaction, find how many moles of each product can be obtained starting with 4.0 mol CH4.
Based on this reaction, find how many moles of CO can be obtained starting with 4.0 mol CH4?
Problem 6b
The following diagram represents a high-temperature reaction between CH4 and H2O. Based on this reaction, find how many moles of each product can be obtained starting with 4.0 mol CH4. Based on this reaction, how many moles of H2 can be obtained starting with 4.0 mol CH4?
Problem 7a
Nitrogen 1N22 and hydrogen 1H22 react to form ammonia 1NH32. Consider the mixture of N2 and H2 shown in the accompanying diagram. The blue spheres represent N, and the white ones represent H. (a) Write the balanced chemical equation for the reaction.
Problem 7d2
Nitrogen 1N22 and hydrogen 1H22 react to form ammonia 1NH32. Consider the mixture of N2 and H2 shown in the accompanying diagram. The blue spheres represent N, and the white ones represent H. (d) If so, how many of which type are left over?
How many N2 molecules are left over?
Problem 7d1
Nitrogen 1N22 and hydrogen 1H22 react to form ammonia 1NH32. Consider the mixture of N2 and H2 shown in the accompanying diagram. The blue spheres represent N, and the white ones represent H. (d) Are any reactant molecules left over, based on the diagram?
Problem 8a
Nitrogen monoxide and oxygen react to form nitrogen dioxide. Consider the mixture of NO and O2 shown in the accompanying diagram. The blue spheres represent N, and the red ones represent O. (a) How many molecules of NO2 can be formed, assuming the reaction goes to completion?
Problem 8c
Nitrogen monoxide and oxygen react to form nitrogen dioxide. Consider the mixture of NO and O2 shown in the accompanying diagram. The blue spheres represent N, and the red ones represent O. (c) If the actual yield of the reaction was 75% instead of 100%, how many molecules of each kind would be present after the reaction was over?
Problem 9a
Write 'true' or 'false' for each statement. (a) We balance chemical equations as we do because energy must be conserved.
Problem 9b
Write 'true' or 'false' for each statement. (b) If the reaction 2 O3(g) → 3 O2(g) goes to completion and all O3 is converted to O2, then the mass of O3 at the beginning of the reaction must be the same as the mass of O2 at the end of the reaction.
Problem 10
A key step in balancing chemical equations is correctly identifying the formulas of the reactants and products. For example, consider the reaction between calcium oxide, CaO(s), and H2O1l2 to form aqueous calcium hydroxide. (b) Is it possible to balance the equation if you incorrectly identify the product as CaOH1aq2, and if so, what is the equation?
- (a) If an automobile travels 350 km with a gas mileage of 9.0 km/L, how many kilograms of CO2 are produced? Assume that the gasoline is composed of octane, C8H181l2, whose density is 0.692 g/mL. (b) Repeat the calculation for a truck that has a gas mileage of 2 km/L.
Problem 11
Problem 11c
Balance the following equations: (c) Al(OH)3(s) + H2SO4(l) → Al2(SO4)3(s) + H2O(l)
Problem 12a,b
Balance the following equations:
(a) HClO4(aq) + P4O10(s) → HPO3(aq) + Cl2O7(l)
(b) Au2S3(s + H2(g) → Au(s) + H2S(g)
Problem 12c
Balance the following equations: (c) Ba3N2(s) + H2O(aq) → Ba(OH)2(aq) + NH3(g)
Problem 12d
Balance the following equations: (d) Na2CO3(aq) + HCl(aq) → NaCl(aq) + H2O(l) + CO2(g)
Problem 13
Balance the following equations:
(a) CaS(s) + H2O(l) → Ca(HS2)2(aq) + Ca(OH)2(aq)
(b) NH3(g) + O2(g) → NO(g) + H2O(g)
(c) FeCl3(s) + Na2CO3(aq) → Fe2(CO3)3(s) + NaCl(aq)
(d) FeS2(s) + O2(g) → Fe2O3(s) + SO2(g)
Problem 14a,b
Balance the following equations: (a) CF4(l) + Br2(g) → CBr4(l) + F2(g) (b) Cu(s) + HNO3(aq) → Cu(NO3)2(aq) + NO2(g) + H2O(l)
Problem 14c
Balance the following equations: (c) MnO2(s) + HCl(aq) → MnCl2(s) + H2O(l) + Cl2(g)
Problem 14d
Balance the following equations: (d) KOH(aq) + H3PO4(aq) → K3PO4(aq) + H2O(l)
Problem 15
Write balanced chemical equations corresponding to each of the following descriptions: (a) Potassium cyanide reacts with an aqueous solution of sulfuric acid to form hydrogen cyanide gas. (b) When an aqueous solution of ammonium nitrite (NH4NO2) reacts with an aqueous solution of potassium hydroxide, ammonia gas, water and metal nitrate is formed. (c) When hydrogen gas is passed over solid hot iron(III) oxide, the resulting reaction produces iron and gaseous water. (d) When liquid ethanoic acid (CH3COOH) is combusted, carbon dioxide and water are formed.
Problem 16a,b
Write balanced chemical equations to correspond to each of the following descriptions: (a) When sulfur trioxide gas reacts with water, a solution of sulfuric acid forms. (b) Boron sulfide, B2S3(s), reacts violently with water to form dissolved boric acid, H3BO3, and hydrogen sulfide gas.
Problem 16c
Write balanced chemical equations to correspond to each of the following descriptions: (c) Phosphine, PH3(g), combusts in oxygen gas to form water vapor and solid tetraphosphorus decaoxide.
Problem 16d,e
Write balanced chemical equations to correspond to each of the following descriptions: (d) When solid mercury(II) nitrate is heated, it decomposes to form solid mercury(II) oxide, gaseous nitrogen dioxide, and oxygen. (e) Copper metal reacts with hot concentrated sulfuric acid solution to form aqueous copper(II) sulfate, sulfur dioxide gas, and water.
- (a) When the metallic element lithium combines with the nonmetallic element chlorine, Cl2(g), what is the chemical formula of the product? (b) In the balanced chemical equation for this reaction, what is the coefficient in front of the product if the coefficient in front of Cl2(g) is 1?
Problem 17
Problem 18a
(a) When a compound containing C, H, and O is completely combusted in air, what reactant besides the hydrocarbon is involved in the reaction?
Problem 18b
(b) What products form in this reaction?
Problem 18c
(c) What is the sum of the coefficients in the balanced chemical equation for the combustion of one mole of acetone, C3H6O1l2, in air?
Ch.3 - Chemical Reactions and Reaction Stoichiometry