Title: Stoichiometry Exam
Course: Stoichiometry

Q: Which of the following would be investigated in stoichiometry?
- the masses of hydrogen and oxygen in water
- the amount of energy released in chemical reactions
- the mass of potassium required to produce a known mass of potassium chloride
- the types of bonds that break and form when acids react with metals
A: the mass of potassium required to produce a known mass of potassium chloride

Q: A balanced chemical equation allows one to determine the:
- mole ratio of any two substances in the reaction
- energy released in the reaction
- electron configuration of all elements in the reaction
- mechanism involved in the reaction
A: mole ratio of any two substances in the reaction

Q: The coefficients in the chemical equation represent the:
- masses, in grams, of all reactants and products
- relative numbers of moles of reactants and products
- number of atoms in each compound in a reaction
- number of valence electrons involved in the reaction
A: relative numbers of moles of reactants and products

Q: If one knows the mole ratio of a reactant and product in a chemical reaction, one can:
- estimate the energy releaed in the reaction
- calculate the speed of the reaction
- calculate the mass of the product produced from a known mass of reactant
- decide whether the reaction is reversible
A: calculate the mass of the product produced from a known mass of reactant

Q: In the reaction N_2 + 3 H_2 -----> 2 NH_3, what is the mole ration of N_2 to NH_3?
- 1:1
- 1:2
- 1:3
- 2:3
A: 1:2

Q: In the reaction 2 Al_2O_3 ------> 4 Al + 3 O_2, what is the mole ratio of aluminum to oxygen gas?
- 10:6
- 3:4
- 2:3
- 4:3
A: 4:3

Q: Which reactant controls the amount of product formed in a chemical reaction?
- excess reactant
- mole ratio
- composition reactant
- limiting reactant
A: limiting reactant

Q: To determine the limiting reactant in a chemical reaction, one must know the:
- available amount of only one of the reactants
- amount of product formed
- available amount of each reactant
- speed of the reaction
A: available amount of each reactant

Q: What is the ratio of actual yield to the theoretical yield, multiplied by 100?
- mole ratio
- percent yield
- Avogadro yield
- excess yield
A: percent yield

Q: If the percent yield is equal to 100%, then:
- the actual yield is greater than the theoretical yield
- the actual yield is equal to the theoretical yield
- the actual yield is less than the theoretical yield
- there was no limiting reactant
A: the actual yield is equal to the theoretical yield

Q: Given the chemical equation 2 KClO_3 ------> 2 KCl + 3 O_2, how many moles of oxygen gas are produced when {a} moles of KClO_3react completely?
A: {a}*1.5 (formula; values not in the backup's text)

Q: For the reaction HCl + NaOH --------> NaCl + NaOH, how many moles of HCl are required to produce {a} g of water?
A: {a}/18.02 (formula; values not in the backup's text)

Q: For the reaction 2 Na + 2 H_2O -------> 2 NaOH + H_2, how many grams of hydrogen gas are produced when {a} g of water are reacted?
A: {a}/36.04*2.02 (formula; values not in the backup's text)

Q: Given the following reaction:

S_8(s) + 24 F_2(g) -------> 8 SF_6(g)

if {a} x 10^23 molecules of S_8react, how many L of SF_6 gas will be produced at STP?
A: {a}/6.02*8*22.4 (formula; values not in the backup's text)

Q: For the reaction 2 K + Cl_2 -------> 2 KCl, how many grams of KCl can be produced from reacting {a}. g of potassium with 500. grams of chlorine gas?
A: {a}/39.1*58.44 (formula; values not in the backup's text)

Q: For the reaction 2 H_2 + O_2 -------> 2 H_2O, if {a} g of H_2 is mixed with 20.0 g of O_2, how many grams of the excess reagent is left over?
A: {a} - 2.525 (formula; values not in the backup's text)

Q: For the reaction Cl_2 + 2 KBr --------> 2 KCl + Br_2, calculate the percent yield of Br_2 if {a}. g of chlorine gas react with excess KBr to produce 410. g of Br_2.
A: {a}/70.9*159.8/410*100 (formula; values not in the backup's text)