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문제 1
The reaction between reactant A (blue spheres) and reactant B (red spheres) is shown in the following diagram:
Based on this diagram, which equation best describes the reaction? (a) A2 + B¡A2B (b) A2 + 4 B¡2 AB2 (c) 2 A + B4¡2 AB2 (d) A + B2¡AB2
문제 2a
The following diagram shows the combination reaction between hydrogen, H2, and carbon monoxide, CO, to produce methanol, CH3OH (white spheres are H, black spheres are C, red spheres are O). The correct number of CO molecules involved in this reaction is not shown. (a) Determine the number of CO molecules that should be shown in the left (reactants) box.
문제 2b
The following diagram shows the combination reaction between hydrogen, H2, and carbon monoxide, CO, to produce methanol, CH3OH (white spheres are H, black spheres are C, red spheres are O). The correct number of CO molecules involved in this reaction is not shown. (b) Write a balanced chemical equation for the reaction.
문제 3a
The following diagram represents the collection of elements formed by a decomposition reaction. (a) If the blue spheres represent N atoms and the red ones represent O atoms, what was the empirical formula of the original compound?
문제 3b
The following diagram represents the collection of elements formed by a decomposition reaction. (b) Could you draw a diagram representing the molecules of the compound that had been decomposed? Why or why not?
문제 4
The following diagram represents the collection of CO2 and H2O molecules formed by complete combustion of a hydrocarbon. What is the empirical formula of the hydrocarbon?
문제 5a
Glycine, an amino acid used by organisms to make proteins, is represented by the following molecular model. (a) Write its molecular formula.
문제 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.
문제 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.
문제 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?
문제 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?
문제 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.
문제 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?
문제 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?
문제 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?
문제 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?
문제 9a
Write 'true' or 'false' for each statement. (a) We balance chemical equations as we do because energy must be conserved.
문제 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.
문제 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.
문제 11
문제 11c
Balance the following equations: (c) Al(OH)3(s) + H2SO4(l) → Al2(SO4)3(s) + H2O(l)
문제 12a,b
Balance the following equations:
(a) HClO4(aq) + P4O10(s) → HPO3(aq) + Cl2O7(l)
(b) Au2S3(s + H2(g) → Au(s) + H2S(g)
문제 12c
Balance the following equations: (c) Ba3N2(s) + H2O(aq) → Ba(OH)2(aq) + NH3(g)
문제 12d
Balance the following equations: (d) Na2CO3(aq) + HCl(aq) → NaCl(aq) + H2O(l) + CO2(g)
문제 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)
문제 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)
문제 14c
Balance the following equations: (c) MnO2(s) + HCl(aq) → MnCl2(s) + H2O(l) + Cl2(g)
문제 14d
Balance the following equations: (d) KOH(aq) + H3PO4(aq) → K3PO4(aq) + H2O(l)
문제 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.
문제 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.