Problem 160
\(18 \mathrm{~g}\) of glucose \(\left(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\right)\) is added to \(178.2 \mathrm{~g}\) of water. The vapour pressure of water for this aqueous solution at \(100^{\circ} \mathrm{C}\) is (a) \(759.00\) torr (b) \(7.60\) torr (c) \(76.00\) torr (d) \(752.40\) torr
Problem 161
A \(5.25 \%\) solution of a substance is isotonic with a \(1.5 \%\) solution of urea (molar mass \(=60 \mathrm{~g} \mathrm{~mol}^{-1}\) ) in the same solvent. If the densities of both the solutions are assumed to be equal to \(1.0 \mathrm{~g} \mathrm{~cm}^{-3}\), molar mass of the substance will be (a) \(115.0 \mathrm{~g} \mathrm{~mol}^{-1}\) (b) \(105.0 \mathrm{~g} \mathrm{~mol}^{-1}\) (c) \(210.0 \mathrm{~g} \mathrm{~mol}^{-1}\) (d) \(90.0 \mathrm{~g} \mathrm{~mol}^{-1}\)
Problem 162
A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of \(290 \mathrm{~mm}\) at \(300 \mathrm{~K}\). The vapour pressure of propyl alcohol is \(200 \mathrm{~mm}\). If the mole fraction of ethyl alcohol is \(0.6\), its vapour pressure (in \(\mathrm{mm}\) ) at the same temperature will be (a) 300 (b) 700 (c) 360 (c) 350
Problem 163
At \(80^{\circ} \mathrm{C}\), the vapour pressure of pure liquid 'A' is 520 \(\mathrm{mm} \mathrm{Hg}\) and that of pure liquid 'B' is \(1000 \mathrm{~mm} \mathrm{Hg}\). If a mixture solution of 'A' and 'B' boils at \(80^{\circ} \mathrm{C}\) and \(\mathrm{I}\) atm pressure, the amount of 'A' in the mixture is ( \(1 \mathrm{~atm}=\) \(760 \mathrm{~mm} \mathrm{Hg}\) ). (a) \(52 \mathrm{~mol}\) per cent (b) 34 mol per cent (c) 48 mol per cent (d) \(50 \mathrm{~mol}\) per cent
Problem 164
At \(80^{\circ} \mathrm{C}\), the vapour pressure of pure liquid 'A' is 520 \(\mathrm{mm} \mathrm{Hg}\) and that of pure liquid 'B' is \(1000 \mathrm{~mm} \mathrm{Hg}\). If a mixture solution of 'A' and 'B' boils at \(80^{\circ} \mathrm{C}\) and \(\mathrm{I}\) atm pressure, the amount of 'A' in the mixture is ( \(1 \mathrm{~atm}=\) \(760 \mathrm{~mm} \mathrm{Hg}\) ). (a) \(52 \mathrm{~mol}\) per cent (b) 34 mol per cent (c) 48 mol per cent (d) \(50 \mathrm{~mol}\) per cent
Problem 166
A binary liquid solution is prepared by mixing n-heptane and ethanol. Which on of the following statement is correct regarding the behavior of the solution? (a) The solution in non-ideal, showing +ve deviation from Raoult's Law. (b) The solution in non-ideal, showing -ve deviation from Raoult's Law. (c) n-heptane shows tre deviation while ethanol shows -ve deviation from Raoult's Law. (d) The solution formed is an ideal solution.
Problem 167
If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water \(\left(\Delta \mathrm{T}_{\mathrm{p}}\right)\), when \(0.01 \mathrm{~mol}\) of sodium sulphate is dissolved in \(1 \mathrm{Kg}\) of water, is \(\left(\mathrm{K}_{\mathrm{f}}=1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\right)\) (a) \(0.0372 \mathrm{~K}\) (b) \(0.0558 \mathrm{~K}\) (c) \(0.0744 \mathrm{~K}\) (d) \(0.0186 \mathrm{~K}\)
Problem 168
On mixing, heptane and octane form an ideal solution. At \(373 \mathrm{~K}\), the vapour pressures of the two liquid components (heptane and octane) are \(105 \mathrm{kPa}\) and \(45 \mathrm{kPa}\) respectively. Vapour pressure of the solution obtained by mixing \(25.0 \mathrm{~g}\) of heptane and \(35 \mathrm{~g}\) of octane will be (molar mass of heptane \(=100 \mathrm{~g} \mathrm{~mol}^{-1}\) and of octane \(=\) \(114 \mathrm{~g} \mathrm{~mol}^{-1}\) ) (a) \(72.0 \mathrm{kPa}\) (b) \(36.1 \mathrm{kPa}\) (c) \(96.2 \mathrm{kPa}\) (d) \(144.5 \mathrm{kPa}\)
Problem 169
The degree of dissociation \((\alpha)\) of a weak electrolyte, \(\mathrm{A}_{\mathrm{x}} \mathrm{B}_{\mathrm{y}}\) is related to van't Hoff factor (i) by the expression: (a) \(\alpha=\frac{x+y-1}{i-1}\) (b) \(\alpha=\frac{x+y+1}{i-1}\) (c) \(\alpha=\frac{1-1}{(x+y-1)}\) (d) \(\alpha=\frac{1-1}{x+y+1}\)
Problem 170
Ethylene glycol is used as antifreeze in a cold climate. Mass of ethylene glycol which should be added to \(4 \mathrm{~kg}\) of water to prevent it form freezing at \(-6^{\circ} \mathrm{C}\) will be: \(\left(\mathrm{K}_{f}\right.\) for water \(=1.86 \mathrm{~kg} \mathrm{~mol}^{-1}\), and molar mass of ethylene glycol \(=62 \mathrm{~g} \mathrm{~mol}^{-1}\) ) (a) \(204.11 \mathrm{~g}\) (b) \(804.32 \mathrm{~g}\) (c) \(600.20 \mathrm{~g}\) (d) \(302.40 \mathrm{~g}\)
