A 0.500 L solution of 7.50 M hydrochloric acid is used to neutralize a 250.0 g sample of calcium hydroxide. Calcium chloride - a chemical used to control highway dust, strengthen concrete mixes, and add flavor to foods - is produced by the reaction.
2 HCl + Ca(OH)2 → CaCl2 + 2 H2 O
a. How many moles of hydrochloric acid are present in the reaction? There are 0.500 L of 7.50 M hydrochloric acid.
b. How many moles of calcium hydroxide are present in the reaction? There are 250.0 g of calcium hydroxide.
c. Is there enough hydrochloric acid to neutralize all of the calcium hydroxide? Use your answer to part b to determine how many moles of HCl are needed to neutralize that much calcium hydroxide. Compare your answer to part a, and see if there is enough HCl to neutralize all of the calcium hydroxide.
d. How many moles of excess reagent (calcium hydroxide) are left over? Calculate how many moles of calcium hydroxide could be converted by the HCl available, then subtract from your answer to part b.
e. What is the theoretical yield of calcium chloride? Calculate the number of moles of calcium chloride produced from the HCl available (you already did this in part d), then convert that number to grams.
f. If 187 g of calcium chloride were obtained after the neutralization was complete, what was the percent yield? Use your answer to part e to see how many grams theoretically were supposed to be produced.