Question

How many grams of KCl must be added to 75.0g of water to produce a solution that is 2.25molal

Answer 1

Answer: 12.6 grams of KCl must be added to 75.0g of water to produce a solution that is 2.25 molal.

Explanation:

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

$molality=\frac{\text {moles of solute}}{\text {weight of solvent in kg}}$

${\text {moles of solute}}=\frac{\text {given mass}}{Molar mass}}$

$[tex]molality=\frac{\text {given mass}}{\text {Molar mass}}\times {weight of solvent in kg}}$

Putting in the values we get:

$[tex]2.25m=\frac{\text {given mass}}{{74.5}\times 0.075kg$

${\text {given mass}}=12.6grams$

12.6 grams of KCl must be added to 75.0g of water to produce a solution that is 2.25 molal.