Solutions Questions

Benzene and toluene form nearly ideal solutions. At $20^{\circ }\text{C}$, the vapour pressure of benzene is $75\text{torr}$ and that of toluene is $22\text{torr}$. The partial vapour pressure of benzene at $20^{\circ }\text{C}$ for a solution containing $78\text{g}$ of benzene and $46\text{g}$ of toluene in torr is:

Two solutions of a substance (non-electrolyte) are mixed in the following manner: $480\text{mL}$ of $1.5\text{M}$ first solution $+520\text{mL}$ of $1.2\text{M}$ second solution. What is the molarity of the final mixture?

Equimolar solutions in the same solvent have:

If $\alpha$ is the degree of dissociation of ${\text{Na}}_2{\text{SO}}_4$, the van't Hoff's factor ($i$) used for calculating the molecular mass is:

A $5.25\%$ solution of a substance is isotonic with a $1.5\%$ solution of urea (molar mass $=60{\text{g mol}}^{-1}$) in the same solvent. If the densities of both the solutions are assumed to be equal to $1.0{\text{g cm}}^{-3}$, molar mass of the substance will be:

A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of $290\text{mm}$ at $300\text{K}$. The vapour pressure of pure propyl alcohol is $200\text{mm}$. If the mole fraction of ethyl alcohol is $0.6$, its vapour pressure in pure state at the same temperature will be:

$18\text{g}$ of glucose (${\text{C}}_6{\text{H}}_{12}{\text{O}}_6$) is added to $178.2\text{g}$ of water. The vapour pressure of water for this aqueous solution at $100^{\circ }\text{C}$ is:

Density of a $2.05\text{M}$ solution of acetic acid in water is $1.02\text{g/mL}$. The molality of the solution is:

The ionic mobility of alkali metal ions in aqueous solution is maximum for:

Which one of the following statements is false?

Which of the following liquid pairs shows a positive deviation from Raoult’s law?

Which one of the following aqueous solutions will exhibit the highest boiling point?

At $80^{\circ }\text{C}$, the vapour pressure of pure liquid ‘A’ is $520\text{mm Hg}$ and that of pure liquid ‘B’ is $1000\text{mm Hg}$. If a mixture solution of ‘A’ and ‘B’ boils at $80^{\circ }\text{C}$ and $1\text{atm}$ pressure, the amount of ‘A’ in the mixture is ($1\text{atm}=760\text{mm Hg}$):

The vapour pressure of water at $20^{\circ }\text{C}$ is $17.5\text{mm Hg}$. If $18\text{g}$ of glucose (${\text{C}}_6{\text{H}}_{12}{\text{O}}_6$) is added to $178.2\text{g}$ of water at $20^{\circ }\text{C}$, the vapour pressure of the resulting solution will be:

If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water ($\Delta T_f$), when $0.01\text{mol}$ of sodium sulphate is dissolved in $1\text{kg}$ of water, is ($K_f=1.86{\text{K kg mol}}^{-1}$):

On mixing, heptane and octane form an ideal solution. At $373\text{K}$, the vapour pressures of the two liquid components (heptane and octane) are $105\text{kPa}$ and $45\text{kPa}$ respectively. Vapour pressure of the solution obtained by mixing $25.0\text{g}$ of heptane and $35\text{g}$ of octane will be (molar mass of heptane $=100{\text{g mol}}^{-1}$ and of octane $=114{\text{g mol}}^{-1}$):

The degree of dissociation $(\alpha )$ of a weak electrolyte, $A_x{B}_y$ is related to van't Hoff factor $(i)$ by the expression:

Ethylene glycol is used as an antifreeze in a cold climate. Mass of ethylene glycol which should be added to $4\text{kg}$ of water to prevent it from freezing at $-6^{\circ }\text{C}$ will be: ($K_f$ for water $=1.86{\text{K kg mol}}^{-1}$, and molar mass of ethylene glycol $=62{\text{g mol}}^{-1}$)

A $5.2\text{molal}$ aqueous solution of methyl alcohol, ${\text{CH}}_3\text{OH}$, is supplied. What is the mole fraction of methyl alcohol in the solution?

The density of a solution prepared by dissolving $120\text{g}$ of urea (mol. mass $=60\text{u}$) in $1000\text{g}$ of water is $1.15\text{g/mL}$. The molarity of this solution is:

$K_f$ for water is $1.86{\text{K kg mol}}^{-1}$. If your automobile radiator holds $1.0\text{kg}$ of water, how many grams of ethylene glycol (${\text{C}}_2{\text{H}}_6{\text{O}}_2$) must you add to get the freezing point of the solution lowered to $-2.8^{\circ }\text{C}$?