A solution of nonvolatile solute is obtained by dissolving 0.8 g in $0.3 \mathrm{dm}^3$ water has osmotic pressure 0.2 atm at 300 K . Calculate the molar mass of solute.

$$\left[\mathrm{R}=0.082 \mathrm{~atm} \mathrm{dm}^3 \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right]$$

Which of the following molecules is an example of sp hybridization?

A first order reaction takes 40 minute for $20 \%$ decomposition. Calculate its rate constant.

What is the number of moles of water molecules present in a mole of carnallite?