Unit 6 Practice Problems

Question

Na₂CO₃ + 2HCl ---> 2NaCl + H₂O + CO₂

If the reaction above produced an actual yield of 5.67 g of sodium chloride in the lab, which resulted in a 73.3% yield, how many grams of sodium carbonate were reacted?

Theoretical Yield = ________ g

Show work.

Answer 1

You have to work in reverse from the usual percent yield problem: the actual 5.67g is 73.3% of Theoretical Yield TY, so TY = 5.67/0.733 = 7.74g NaCl.

Now to answer grams of Na₂CO₃ reacted: (7.74g NaCl) * (1 mol NaCl / 58.44g NaCl) * (1 mol Na₂CO₃ / 2 mol NaCl) * (106.0g Na₂CO₃ / 1 mol Na₂CO₃) = 7.02g Na₂CO₃.