Molality Calculation: How Much NaCl is Needed for a 0.35 Molal Solution?

[Equilibrium]

Homework Statement

How many grams of NaCl must you add to 750g of water to make a 0.35 molal solution?

Ans. 7.59g

Homework Equations

$$molality=\frac{mol_{solute}}{kg_{solvent}}$$
MW of NaCl = 23 + 35.45 = 58.45 g/mole

The Attempt at a Solution

$$0.35mol/kg=\frac{mass(\frac{1mole}{58.45g})}{0.750kg}$$
$$mass = 15.33g$$

 

[Borek]

Looks OK.