What is the percent weight in weight strength if 50 grams of NaCl is dissolved in 300 mL of solvent with specific gravity of 1.2?

Answer 1

Percent weight means grams of solute / grams of solution (x100%)

grams solute = 50 g NaCl

To find grams of solution, we use the specific gravity, and assuming the value give (1.2) is relative to water, we can convert this to a density of 1.2 g/ml.

300 ml solvent x 1.2 g / ml = 360 g solvent

Total mass of solution = 50 g NaCl + 360 g solvent = 410 g

% by mass (% weight) = 50 g / 410 g (x100%) = 12%