Question

A nurse needs to make a 0.081 M CaCl2 solution in which to dissolve drugs for a patient. (Atomic Mass of Calcium is 40.1. Chlorine is 35.5) What percent solution is this? Round answer to the tenths place.

Answer 1

0.081 M means 0.081 moles present in 1 litre

molar mass mass of CaCl2 = 40.1 + 2 x 35.5 = 111.1 g/mol

moles = mass / molar mass

0.081 = mass / 111.1

mass = 8.999 g = 9 .0 g

% solution = ( mass / volume ) x 100

                    = 9 .0 x 100 / 1000

                     = 0.90

% of solution = 0.90 %