Percent Yield WS
1. What is theoretical yield? _____________________________________________________________
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2. What is actual yield? _________________________________________________________________
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3. Write the formula for percent yield.
4. Percent yield tells us how __________________________ the reaction is. (pg 386)
5. List two factors that might cause percent yield to be less than 100%.
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6. 9.00 g of Al react with an excess of H3PO4 in this reaction
2 Al(s) + 2 H3PO4(aq) → 2 AlPO4(aq) + 3 H2(g)
a)
b)
What mass of AlPO4 could theoretically be produced in this reaction?
What is the percent yield if you actually only recovered 30.0 g of AlPO4.
7. 105 g of H3PO4 is reacted using the same equation from #1 above.
a)
What is the theoretical yield of AlPO4 for this reaction?
b)
What is the % yield for the reaction if you recovered 95.4 g of AlPO4?
8. When 320 g of octane is burned in excess oxygen, 392 g of water is recovered.
2 C8H18 + 25 O2 → 16 CO2 + 18 H2O
a)
Determine the theoretical yield of water.
b)
Determine the % yield.
9. 2.85 g Al(NO3)3 combines with 1.82 g NaOH, and 0.996 g Al(OH)3 is recovered according to the
following equation.
Al(NO3)3 + 3 NaOH → Al(OH)3 + 3 NaNO3
a) Determine the theoretical yield of Al(OH)3. (hint: find lim. reactant 1st and use it for yield)
b) Determine the % yield.
10. In the following reaction
3 H2 + N2 → 2 NH3
5.78 g of H2 and 6.28 g N2 are reacted, and 5.05 g of NH3 is recovered.
a)
Determine the theoretical yield for NH3. (hint: find lim. reactant 1st and use it for yield)
b)
Determine the % yield for NH3.
11. A student places an iron nail (Fe) with a mass of 2.32 g into a flask containing a solution of CuSO4.
The nail reacts completely, leaving a quantity of copper in the bottom of the flask. The student finds the
mass of recovered copper to be 2.51 g. The equation for this reaction is
Fe + CuSO4 → FeSO4 + Cu
a)
What is the percent yield?