Question

Consider the following reaction: 2NaCl(aq) + H2O(l) -> Cl2(g) + H2(g) + 2NaOH(aq)
A 10.0g sample of sodium chloride was placed in 10.0 g of water. If 3.85 g of Cl2 was obtained, what was
the percent yield of Cl2?

Answer 1

This is a limiting reagent problem; I know that because amounts for BOTH reactants are given. I do these problems by solving two stoichiometry problems. The first, use 10 g water (ignore the NaCl), convert to moles H2O, convert to moles Cl2 using the coefficients in the balanced equation. Then use 10 g NaCl(ignore the H2O) and convert to moles NaCl, use the coefficients in the balanced equation to convert moles NaCl to moles Cl2. You will obtain two answers for moles Cl2 and the correct one in limiting reagent problems is ALWAYS the smaller one and the reagent producing that value is the limiting reagent. Use the smaller value and convert to grams. g = moles x molar mass.
That is the theoretical yield.
%yield = (actual yield/theoretical yield)*100 = ?