Question

What will be the molality of the solution containing $18.25\, g$ of $HCl$ gas in $500\, g$ of water?

• A. $0.1\,m$
• B. $1\,M$
• C. $0.5\,m$
• D. $1\,m$

Answer 1

Answer: (D)

$1\,m$

Answer 2

Molality $(m) = \frac{\text{No. of moles of solute}}{\text{Mass of solvent (in kg)}}$ Molality $= \frac{W_B \times1000}{ W_A(in g)} = \frac{18.25\times 1000}{36.5\times 500}$ ($\therefore$ Molar mass of $HCl = 36.5\,g\, mol^{-1}$ ) $=1\, m$