chem chapter 9

in the reaction represented by the equation 2Al2O3 ---> 4Al + 3O2, what is the mole ratio of aluminum to oxygen?

4:3

for the reaction represented by the equation CH4 + 2O2 ---> 2H2O + CO2, calculate the percentage yield of carbon dioxide if 1000. g of methane react with excess oxygen to produce 2300. g of carbon dioxide.

83.88%

what is the measured amount of a product obtained from a chemical reaction?

actual yield

if one knows the mole ratio of a reactant and a product in a chemical reaction, one can ___.

calculate the mass of the product produced from a known mass of a reactant

the units of molar mass are ___.

g/mol

in most chemical reactions, the amount of product obtained is ___.

less than the theoretical yield

each of the four types of reaction stoichiometry problems requires using a ___.

mole ratio

in the chemical reaction represented by the equation wA + xB ---> yC + zD, a comparison of the number of moles of A to the number of moles of C would be a ___.

mole ratio

given the equation 3A + 2B ---> 2C, the starting mass of A, and its molar mass, and you are asked to determine by the moles of C produced, your first step in solving the problem is to multiply the given mass of A by ___.

1 mol A/ molar mass A

which coefficients correctly balance the formula NH4NO2 --> N2 + H2O?

1, 1, 2

in the reaction represented by the equation N2 + 3H2 ---> 2NH3, what is the mole ratio of nitrogen to ammonia?

1:2

for the reaction represented by the equation C + 2H2 ---> CH4, how many moles of hydrogen are required to produce 10 mol of methane, CH4?

20 mol

in the reaction represented by the equation C + 2H2 ---> CH4, what is the mole ratio of hydrogen to methane?

2:1

which equation is not balanced?

2H2 + 02+ H2O

the Haber process for producing ammonia commercially is represented by the equation N2 (g) + 3H2 (g) ---> 2NH3 (g). to completely convert 9.0 mol hydrogen gas to ammonia gas, how many moles of nitrogen gas are required?

3.0 mol

in the reaction represented by the equation N2 + 3H2 ---> 2NH3, what is the mole ratio of hydrogen to ammonia?

3:2

in the equation 2KClO3 ---> 2KCl + 3O2, how many moles of oxygen are produced when when 3.0 mol of KClO3 decompose completely?

4.5 mol

for the reaction represented by the equation Mg + 2HCl ---> H2 + MgCl2, calculate the percentage yield of magnesium chloride if 100. g of magnesium react with excess hydrochloric acid to yield 330. g of magnesium chloride.

84.2%

a balanced chemical equation allows one to determine the ___.

mole ratio of any two substances in the reaction

a chemist interested in the efficiency of a chemical reaction would calculate the ___.

percentage yield

what is the ratio of the actual yield to the theoretical yield, multiplied by 100%?

percentage yield

what is the study of the mass relationships among reactants and products in a chemical reaction?

reaction stoichiometry

the coefficients in a chemical equation represent the ___.

relative numbers of moles of reactants and products

a chemical equation is balanced when the ___.

same number of each kind of atom appears in the reactants and in the products

which brand of chemistry deals with the mass relationships of elements in compounds and the mass relationships among reactants and products in chemical reactions?

stoichiometry

in the chemical equation wA + xB ---> yC + zD, if one knows the mass of A and the molar masses of A, B, C, and D, one can determine ___.

the mass of any of the reactants or products

for the reaction represented by the equation 2H2 + O2 ---? 2H2O, how many moles of water can be produced from 6.0 mol of oxygen?

12 mol

when the formula equation Fe3O4 + Al ---> Al2O3 + Fe is correctly balanced the coeffient of Fe is the number ___.

9

for the reaction represented by the equation N2 + 3H2 ---> 2NH3, how many moles of nitrogen are required to produce 18 mol of ammonia?

9.0 mol

for the reaction represented by the equation Cl2 + 2KBr ---> 2KCl + Br2, calculate the percentage yield if 200. g of chlorine react with excess potassium bromide to produce 410. g of bromine.

91.0%

for the reaction represented by the equation SO3 + H2O ---> H2SO4, calculate the percentage yield if 500. g of sulfur trioxide react with excess water to produce 575 g of sulfuric acid.

93.9%

to balance a chemical equation, it may be necessary to adjust the ___.

coefficients

a determination of the masses and number of moles of sulfur and oxygen in the compound sulfur dioxide would be studied in ___.

composition stoichiometry

what is the study of the mass relationships of elements in compounds?

composition stoichiometry

if one knows the mass and molar mass of reactant A and the molar mass of product D in a chemical reaction, one can determine the mass of product D produced by using the ___.

mole ratio of D to A from the chemical equation

in what kind of reaction do two or more substances combine to form a new compound?

synthesis reaction

if the percentage yield is equal to 100%, then ___.

the actual yield is equal to the theoretical yield

which of the following would not be studied in the branch of chemistry called stoichiometry?

the amount of energy required to break the ionic bonds in calcium fluoride

which of the following would be investigated in reaction stoichiometry?

the mass of potassium required to produce a known mass of potassium chloride

what is the maximum possible amount of product obtained in a chemical reaction?

theoretical yield