Question

what is the molality of a solution that is obtained by dissolving 2.922 g of nacl into 1000.0 g of water if the molar mass of nacl is 58.44 g/mol? use molality=moles of solute/kilograms of solvent

Answer 1

1000cm = 1 mol
2.922 g of nacl / 58.44 = 0.05 * 1000 = 50 g/mol

Answer 2

Answer: 0.05 m

Explanation:

Molality of a solution is defined as the number of moles of solute dissolved per kg of the solvent.

$Molality=\frac{n\times 1000}{W_s}$

where,

n = moles of solute

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{2.922}{58.44}=0.05moles$

$W_s$ = weight of solvent in g=1000 g

Molality =$\frac{n\times 1000}{W_s}=\frac{0.05\times 1000}{1000}=0.05m$

Thus molality of the solution is 0.05m