Which of the following is a molecular formula of cyclohexylamine?

Calculate heat required to convert 9 g of liquid water to water vapours from following equations.

$$\begin{aligned} & \mathrm{H}_{2(\mathrm{~g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \longrightarrow \mathrm{H}_2 \mathrm{O}_{(\mathrm{g})} \Delta \mathrm{H}=-57 \mathrm{kCal} \\ & \mathrm{H}_{2(\mathrm{~g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \longrightarrow \mathrm{H}_2 \mathrm{O}_{(\mathrm{g})} \Delta \mathrm{H}=-68.3 \mathrm{kCal} \end{aligned}$$

Which from following compounds is NOT in solid state at $25^{\circ} \mathrm{C}$ ?

Calculate the molar mass of solute when 4 g of it dissolved in $1 \mathrm{dm}^3$ solvent has osmotic pressure 2 atm at 300 K . [R $\left[=0.082 \mathrm{~dm}^3 \mathrm{~atm} \mathrm{~K} \mathrm{~mol}^{-1}\right]$