Question

For the following reaction, 4.24 grams of zinc oxide are mixed with excess water. The reaction yields 4.39 grams of zinc hydroxide. zinc oxide (s) + water (1) - zinc hydroxide (aq) What is the theoretical yield of zinc hydroxide ? What is the percent yield for this reaction? grams Submit Answer Retry Entire Group 4 more group attempts remaining

Answer 1

Question 1

Balanced equation:
ZnO + H2O ====> Zn(OH)2
Reaction type: synthesis

Mass of ZnO = 4.24 g

Moles of ZnO = 4.24 g / 81.38 g/mol =  0.05210 Mole s

Moles of Zn(OH)2 produced =  0.05210 mol

Theoretical Mass of Zn(OH)2 =  0.05210 mol x 99.39 g/mol = 5.178 g

Actual yield of  Zn(OH)2 = 4.39 g

Percentage yield = 4.39 g x 100 % / 5.178 g = 84.78 %

Question 2

Balanced equation:
KHSO4 + KOH ====> K2SO4 + H2O
Reaction type: double replacement

Mass of KHSO4 = 5.62 g

Moles of KHSO4 = 5.62 g / 136.168 g/mol =  0.04127 Mole s

Moles of K2SO4 produced =  0.04127 mol

Theoretical Mass of K2SO4 =  0.04127 mol x 174.25 g/mol = 7.192 g

Actual yield of  K2SO4 = 5.78 g

Percentage yield = 5.78 g x 100 % /7.192g = 80.36 %