Question

What is the molality of 49 grams of NaCl in 469 grams of H2O (water)

Answer 1

Answer : The molality of sodium chloride is, 1.79 m

Explanation :

To calculate the molality of solution, we use the equation:

$\text{Molality}=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

Where,

$m_{solute}$ = Given mass of solute (sodium chloride) = 49 g

$M_{solute}$ = Molar mass of solute (sodium chloride) = 58.5 g/mol

$W_{solvent}$ = Mass of solvent (water) = 469 g

Now put all the given values in above equation, we get:

$\text{Molality of }NaCl=\frac{49g\times 1000}{58.5g/mol\times 469kg}\\\\\text{Molality of }NaCl=1.79mol/kg=1.79m$

Hence, the molality of sodium chloride is, 1.79 m