Answer:
There should react 1008.3 grams KOH
Explanation:
Step 1: Data given
yield = 20.85 %
actual yield of H2O = 67.5 grams
Molar mass of H2SO4 = 98.08 g/mol
Molar mass of H2O = 18.02 g/mol
Molar mass of KOH = 56.11 g/mol
Step 2: The balanced equation
H2SO4 + 2KOH ⇒ K2SO4 + 2H2O
Step 3: Calculate moles of H2O
Moles H2O = Mass H2O / Molar mass H2O
Moles H2O = 67.5 grams / 18.02 g/mol
Moles H2O = 3.746 moles
Step 4: Calculate theoretical yield
% yield= (actual yield/theoretical yield)*100%
Theoretical yield= (Actual yield/Percent yield) * 100%
Theoretical yield = (3.746 moles /20.85) *100%
Theoretical yield = 17.97 moles of H2O
Step 5: Calculate moles of KOH
For 2 moles of H2O produced, we need 2 moles of KOH
For 17.97 moles of H2O produced, we need 17.97 moles of KOH
Step 6: Calculate mass of KOH
Mass KOH =moles KOH * Molar mass KOH
Mass KOH = 17.97 moles * 56.11 g/mol
Mass KOH = 1008.3 grams
There should react 1008.3 grams KOH