Question

A student reacted 75.00 mL of 2-propanol (d=0.786 g/ml) with 5.50 mL of concentrated sulfuric acid (18.4M) to produce diisoproyl ether (d=0.725 g/ml). After performing the synthesis the student recoverd 38.04 g of diisopropyl ether. What was the student's percent yield?

Answer 1

Mass of propanol = density x volume

= 0.786 g/mL x 75 mL

= 58.95 g

Moles of propanol = mass/molecular weight

= 58.95g / 60.09 g/mol

= 0.981 mol

Moles of H2SO4 =molarity x volume

= 18.4 mol/L x 5.50 mL x 1L/1000 mL

= 0.1012 mol

The balanced reaction

2 C3H7OH + H2SO4 = C6H14O + H2O

2 mol of 2-propanol produces = 1 mol of diisoproyl ether

0.981 mol 2-propanol produces = 0.981/2 = 0.4905 mol of diisoproyl ether

Theoretical yield of diisoproyl ether = moles x molecular weight

= 0.4905 mol x 102.18 g/mol

= 50.12 g

Actual yield = 38.04 g

% yield = actual yield x 100 / theoretical yield

= 38.04*100/50.12

= 75.90 %