Which of the following is the molecular formula of halous acid of chlorine?

Calculate the enthalpy of solution of potassium chloride if its $\Delta_{\mathrm{L}} \mathrm{H}=700 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $\Delta_{\text {hyd }} H=-680 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Calculate the number of atoms present in 1 g of an element if it forms fcc unit cell structure. $\left[\rho \times \mathrm{a}^3=6.8 \times 10^{-22} \mathrm{~g}\right]$

Which carbon atoms of $\alpha-D$ glucose and $\beta-D$ fructose respectively forms glycosidic linkage in sucrose?