Question

How many grams of hydrogen peroxide (H2O2) must be added to 1,500 mL of water to produce a concentration of 1.33 m (molal solution)? (Recall that the density of water is 1.0 gram/mL.)

Answer 1

Given:

1,500 mL of water

1.33 m (molal solution

Required:

grams of hydrogen peroxide (H2O2

solution:

1.33 molal = 1.33 m = 1.33 moles H2O2/kg water

1 gram/liter of water (1 liter/1000 mL) (1500mL)(1 kg/1000g) = 0.0015 kg water

1.33 moles H2O2/kg water (0.0015 kg water) = 0.001995 moles H2O2

Molar mass of H2O2 = 34 g/mol

0.001995 moles H2O2 (34 g/mol) = 0.068 grams H2O2