A semi-molar (1 Litre) solution of HCl solution on heating lost 2.675 g of hydrogen chloride and volume of solution shrunk to 750 mL. The molarity of new solution will be :

$\text{ moles }=\text{ molarity }\times \text{ bolume in litre }$

$\begin{array}{l}=\left(\frac{1}{2}\right)\times \left(1\right)\\ =0.5\end{array}$

$\text{ mass }=\text{ moles }\times \text{ molar mass }$

$=0.5\times 36.5=18.25 \mathrm{grams}$

$\text{ loss in mass }=2.675\text{ grams }$

$\therefore$$\text{ final mass }=18.25-2.675$

$\begin{array}{l}=15.575\text{ grams }\\ \therefore \text{ moles }=\frac{15.575}{36.5}=0.4267\end{array}$

$\mathrm{Final} \mathrm{volume}=750 \mathrm{ml}=0.75 \mathrm{grams}$

$\therefore \text{ Molarity }=\frac{0.4267}{0.75}=0.5689\mathrm{M}$

$~0.569\mathrm{M}$