Question

What would be the molality of $20\%$ (mass / mass) aqueous solution of $KI$?
(molar mass of $KI=166gmo{l}^{-1}$)

• A. 1.08
• B. 1.48
• C. 1.51
• D. 1.35
• E. 3

Answer 1

Answer: (C)

$\frac{W}{W}\%=20$
$100gm$ solution has $20gmKI$
$80gm$ solvent has $20gmKI$
$m=\frac{\frac{20}{166}}{\frac{80}{1000}}=\frac{20\times 1000}{166\times 80}=1.506\simeq 1.51mol/kg$