Question

What is the molarity of $HCl$ in a solution prepared by dissolving $5.5g$ $HCl$ in $200g$ ethanol if the density of the solution is $0.79g$ $m{L}^{-1}$?

• A. $21M$
• B. $0.93M$
• C. $6\times {10}^{4}M$
• D. $0.58M$

Answer 1

The correct option is D $0.58M$

$Density=0\cdot 79gm{L}^{-1}$

$0\cdot 79g$ in $1ml$ of solution.

$1=\frac{1}{0\cdot 79}gm$

$(200+5\cdot 5)gm=\frac{205\cdot 5}{0\cdot 79}$

$=260\cdot 12ml$ (solution)

$M=\frac{5\cdot 5}{36\cdot 5}\times \frac{1000}{260\cdot 12}$

$M=0\cdot 579=0\cdot 58M$