Chapter 11 review
1.
Silver sulfide (Ag2S) is the common tarnish on silver objects. What weight of silver
sulfide can be made from 1.23 g of hydrogen sulfide (H2S) obtained from a rotten
egg? The reaction of formation of silver sulfide is given below:
Ag(s) + H2S(g) + O2(g) Ag2S(s) + H2O(l) (Equation must first be balanced.)
2. A somewhat antiquated method for preparing chlorine gas involves heating
hydrochloric acid with pyrolusite (manganese dioxide), a common manganese ore.
(Reaction given below.) How many g of HCl react with 5.69 g of manganese dioxide?
HCl(aq) + MnO2(s)  H2O(l) + MnCl2 (aq) + Cl2(g) (Equation must first be balanced.)
3. Given the following equation: 2 KClO3 ---> 2 KCl + 3 O2
How many moles of O2 can be produced by letting 12.00 moles of KClO3 react?
4. Given the following equation: Na2O + H2O ---> 2 NaOH
How many grams of NaOH is produced from 120 grams of Na2O? How many grams of
Na2O are required to produce 160 grams of NaOH?
5. Given the following equation: 8 Fe + S8 ---> 8 FeS
What mass of iron is needed to react with 16.0 grams of sulfur? How many grams of
FeS are produced?
6. Given the following equation: 2 NaClO3 ---> 2 NaCl + 3 O2
12.00 moles of NaClO3 will produce how many grams of O2? How many grams of NaCl
are produced when 80.0 grams of O2 are produced?
7. Given the following equation: Cu + 2 AgNO3 ---> Cu(NO3)2 + 2 Ag
How many moles of Cu are needed to react with 3.50 moles of AgNO 3? If 89.5
grams of Ag were produced, how many grams of Cu reacted?
8. The average human requires 120.0 grams of glucose (C6H12O6) per day. How many
grams of CO2 (in the photosynthesis reaction) are required for this amount of
glucose? The photosynthetic reaction is:
6 CO2 + 6 H2O ---> C6H12O6 + 6 O2
Chemistry: Limiting Reactant Problems
Directions: Solve each of the following problems. Show your work, including proper units, to
earn full credit.
1. According to the balanced chemical equation, how many atoms of silver will be produced from
combining 100 g of copper with 200 g of silver nitrate?
Cu(s) + 2 AgNO3(aq)  Cu(NO3)2(aq) + 2 Ag(s)
2. At STP, what volume of “laughing gas” (dinitrogen monoxide) will be produced from 50 g of
nitrogen gas and 75 g of oxygen gas?
3. Carbon monoxide can be combined with hydrogen to produce methanol, CH3OH. Methanol is
used as an industrial solvent, as a reactant in some synthesis reactions, and as a cleanburning fuel for some racing cars. If you had 152.5 g of carbon monoxide and 24.5 g of
hydrogen gas, how many grams of methanol could be produced?
4. How many grams of water will be produced from 50 g of hydrogen and 100 g of oxygen?
5. An unbalanced chemical equation is given as:
___N2H4(l) + ___N2O4(l)  ___N2(g) + ___H2O(g).
If you begin with 400 g of N2H4 and 900 g of N2O4…
A. Find the number of grams of water produced, assuming the reaction goes to
completion.
B. Find the number of grams of nitrogen produced, assuming the reaction goes to
completion.
C. Find the mass of excess reactant left over at the conclusion of the reaction.
6. An unbalanced chemical equation is given as: ___Na(s) + ___O 2(g)  ___Na2O(s)
If you have 100 g of sodium and 60 g of oxygen…
A. Find the number of moles of sodium oxide produced.
B. Find the mass of excess reactant left over at the conclusion of the reaction.