Question

What is the percent yield of H2 if 75g Mg reacting with excess HNO3 produces 5.5g H2?

Answer 1

Mg + HNO3 --> Mg(NO3)2 + H2
1. balance the equation
2. convert 75g of Mg to moles of Mg
3. use the balanced equation to convert moles of Mg to moles of H2
4. convert moles of H2 to grams of H2. this is your actual yield
5. percent yield = (actual yield)/(theoretical yield) * 100%