CH. 9 PART 2 WKST: LIMITING REAGENTS AND PERCENT YIELD
1. A reaction combines 133.48 g of lead (II) nitrate with 45.010 g of sodium hydroxide.
Pb(NO3)2
2 (s) + NaNO3 (aq)
a) Which reactant is limiting? Which is in excess? PB(NO3)2 is Limiting
NAOH is Excess
b) How much lead (II) hydroxide is formed? 97.1g
c) How much of the excess reactant is left over? 12.8g
d) If the actual yield of lead (II) hydroxide were 80.02 g, what was the percent yield? 82.4%
2. A reaction combines 64.81 grams of silver nitrate with 92.67 grams of potassium bromide.
AgNO3
3 (aq)
a) Which reactant is limiting? Which is in excess? AGNO3 is Limiting
KBR Excess
b) How much silver bromide is formed? 72g
c) How much of the excess reactant is left over? 47.3g
d) If the actual yield of silver bromide were 14.77 g, what was the percent yield? 20.5%
3. Hydrazine (N2H4) is used as rocket fuel. It reacts with oxygen to form nitrogen and water.
N2H4 (l) + O2
2 (g) + H2O (g)
a) How many liters of N2 (at STP) form when 1.0 kg N2H4 reacts with 1.0 kg O2? 700L
b) How many grams of the excess reagent remain after the reaction? No Excess
4. When 50.0 g of silicon dioxide is heated with an excess of carbon, 32.2 g of silicon carbide is
produced.
SiO2
a) What is the percent yield of this reaction? 64.4%
b) How many grams of CO gas are made? 70g
5. If the reaction below proceeds with a 96.8% yield, how many kilograms of CaSO4 are formed
when 5.24 kg SO2 reacts with an excess of CaCO3 and O2?
CaCO3 (s) + SO2 (g) + O2
4 (s) + CO2 (g) 8.3*10^-4