# Molality homework problem

1. Mar 8, 2013

### Equilibrium

1. The problem statement, all variables and given/known data
How many grams of NaCl must you add to 750g of water to make a 0.35 molal solution?

Ans. 7.59g
2. Relevant equations
$$molality=\frac{mol_{solute}}{kg_{solvent}}$$
MW of NaCl = 23 + 35.45 = 58.45 g/mole

3. The attempt at a solution
$$0.35mol/kg=\frac{mass(\frac{1mole}{58.45g})}{0.750kg}$$
$$mass = 15.33g$$

2. Mar 9, 2013

Looks OK.