Question

calculate the molality of potassium carbonate sol which is firmed by dissolving 2.5g of it in 1liter sol density of the sol is 0.85g per ml

Answer 1

Explanation:

Mass of solute ( K2CO3 ) = 2.5 gram

= 0.85 g/ml

Density of solvent = 0.85 × 10^-3 kg/ 10^-3 litres

=0.85 kg /L

Volume of solvent = 1L

Mass of solvent = volume × density

=1L × 0.85 kg/L

= 0.85 kg

Now, molality(m) = no. of moles of solute / mass of solvent in kg

=(mass of solute / molar mass of solute) / 0.85

=(2.5g / 138g/mol)/0.85

= 0.021molal