Question

Calculate the molality of a solution when 10g of potassium hydroxide dissolved in 500g of water​

Answer 1

Answer:

$\large Molality=0.36 \ mol/kg$

Explanation:

Given mass ( mass of solute ) = 10 g

Molar mass of KOH = 56 u

Mass of solution = 500 g

Mass of solvent = Mass of solution - mass of solute

Mass of solvent = 500 g - 10 g = 490 g.

Now we have formula for Molality

$\large Molality=\dfrac{mass \ of \ solute}{Molar \ mass \times mass \ of \ solvent}\times1000 \ mol/kg$

Put the value here we get

$\large Molality=\dfrac{10}{56 \times 490}\times1000 \ mol/kg \\\\\\\large Molality=\dfrac{1000}{56 \times 49} \ mol/kg\\\\\\\large Molality=\dfrac{1000}{2,744} \ mol/kg\\\\\\\large Molality=0.36 \ mol/kg$

Thus we get answer.