41g of magnesium react with 11.86g of hydrochloric acid. Calculate the theoretical yield of the reaction. If the actual yield is 12g magnesium chloride, calculate the percent yield of the reaction.

Answer 1

Write the correctly balanced equation: Mg(s) + 2HCl(aq) ==> MgCl₂(aq) + H₂(g)

Find the limiting reactant:

For Mg: 41 g Mg x 1 mol Mg/24.3 g x 1 mol MgCl2/mol Mg x 95.2 g /mole MgCl2 = 161 g MgCl2

For HCl: 11.86 g HCl x 1 mol HCl/36.5 g x 1 mol MgCl2/2 mol HCl x 95.2 g/mol MgCl2 = 15.47 g MgCl2

HCl is limiting and dictates theoretical yield of MgCl2 which is 15.47 g = Theoretical yield = 15 g (2 sig figs)

% yield = 12 g/15 g (x100%) = 80% yield