Chapter 8

The boiling point of \(\mathrm{CHCl}_{3}\) was raised by \(0.323^{\circ} \mathrm{C}\) when \(0.37 \mathrm{~g}\) of naphthalene was dissolved in \(35 \mathrm{~g} \mathrm{CHCl}_{3} .\) Calculate the molecular weight of naphthalene. \(K_{\mathrm{b}}^{\prime}\) for \(\mathrm{CHCl}_{3}=3.9 \mathrm{~K} \mathrm{~mol}^{-1} \mathrm{~kg}\).

What will be the boiling point of bromine when \(174.5 \mathrm{mg}\) of octaatomic sulphur is added to \(78 \mathrm{~g}\) of bromine. \(K_{\mathrm{b}}^{\prime}\) for \(\mathrm{Br}_{2}\) is \(5.2 \mathrm{~K}\) mol \({ }^{1} \mathrm{~kg}\) and b.pt. of \(\mathrm{Br}_{2}\) is \(332.15 \mathrm{~K}\).

The partial pressure of ethane over a saturated solution containing \(6.56 \times 10^{-2} \mathrm{~g}\) of ethane is 1 bar. If the solution contains \(5.00 \times 10^{-2} \mathrm{~g}\) of ethane, then what shall be the partial pressure of the gas.

Calculate the concentration of \(\mathrm{CO}_{2}\) in a soft drink that is bottled with a partial pressure of \(\mathrm{CO}_{2}\) of 4 atm over the liquid at \(25^{\circ} \mathrm{C}\). The Henry's law constant for \(\mathrm{CO}_{2}\) in water at \(25^{\circ} \mathrm{C}\) is \(3.1 \times 10^{-2} \mathrm{~mol} /\) litre-atm .