EASY

Earn 100

The elevation of boiling point and depression of freezing point of a certain solution of a monobasic acid $HA$ in benzene are ${ΔT}_{b}$ and ${ΔT}_{f}$ , respectively. $HA$ exists usually as a monomer, but it dissociates into ions (with degree of dissociation $α$ ) at the boiling point $T_{b}$ of the solution, whereas at the freezing point $T_{f}$ of the solution, $HA$ exists as $(HA)_{n}$ with a fixed value of $n$ . The molal boiling point elevation constant and molal freezing point depression constant are $K_{b}$ and $K_{f}$ , respectively. The correct expression for $n$ is

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Important Questions on Solutions

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The elevation in the boiling point of an aqueous solution of

NaCl

0.01 ° C

. If its van't Hoff factor is

1.92,

the molality of

NaCl

solution is ___

(K_{b}

for water

= 0.52 K kg {mol}^{- 1})

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

Solute

' X'

dimerises in water to the extent of

80 %

2.5 g

' X'

100 g

of water increases the boiling point by

0.3 ° C

. The molar mass of

' X'

[K_{b} = 0.52 K {kgmol}^{- 1}]

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The boiling point of benzene is

353.23 K

. When

1.80 g

of non-volatile solute was dissolved in

90 g

of benzene, the boiling point of is raised to

354.11 K

. Calculate the molar mass of the solute. (

K_{b}

for benzene is

2.53 K Kg {mol}^{- 1}

)

HARD

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

If a compound

AB

dissociates to the extent of

75 %

in an aqueous solution, the molality of the solution which shows a

2.5 K

rise in the boiling point of the solution is ___ molal. (Rounded-off to the nearest integer)

[K_{b} = 0.52 K kg {mol}^{- 1}]

EASY

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

1 g

of a non-volatile non-electrolyte solute is dissolved in

100 g

of two different solvents

A

and B whose ebullioscopic constants are in the ratio of

1 : 5

. The ratio of the elevation in their boiling points,

\frac{∆ T_{b} (A)}{∆ T_{b} (B)}

, is: (assuming they have the same molar mass)

EASY

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The boiling point (in

{}^{\circ}C

) of

0.1

molal aqueous solution of

{CuSO}_{4} . 5 H_{2} O

1

bar is closest to: [Given: Ebullioscopic (molal boiling point elevation) constant of water,

K_{b} = 0.512 K {kgmol}^{- 1}]

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

180 g

of glucose,

C_{6} H_{12} O_{6}

is dissolved in

1 kg

of water in a saucepan. At what temperature the solution will boil at

1.013

bar?

(K_{b}

for water is

0.52 K kg {mol}^{- 1})

EASY

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

Which of the following aqueous solution will have the boiling point

102.2 ° C ?

The molal elevation constant for water is

2.2 K kg {mol}^{- 1} .

EASY

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The elevation of boiling point of

0.10 m

aqueous

{CrCl}_{3} . {xNH}_{3}

solution is two times that of

0.05 m

aqueous

{CaCl}_{2}

solution. The value of

x

\dots \dots \dots \dots . .

[Assume

100 %

ionisation of the complex and

{CaCl}_{2},

coordination number of

Cr

6,

and that all

{NH}_{3}

molecules are present inside the coordination sphere]

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

58.5 g of NaCl and 180 g

of glucose were separately dissolved in

1000 mL

of water. Identify the correct statement regarding the elevation of boiling point (b.pt.) of the resulting solutions.

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

1

molal aqueous solution of an electrolyte

A_{2} B_{3}

60 %

ionised. The boiling point of the solution at

1 atm

is _____

K

. (Rounded-off to the nearest integer) [Given

K_{b}

for

(H_{2} O) = 0.52 K kg {mol}^{- 1}

]

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The boiling point of

0.2 m o l k g^{- 1}

solution of X in water is greater than equimolal solution of Y in water. Which one of the following statements is true in this case?

HARD

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

${AB}_{2}$ is $10 %$ dissociated in water to $A^{2 +}$ and $B^{-}$ . The boiling point of $10.0$ molal aqueous solution of ${AB}_{2}$ is-- ${}^{\circ}C$ . (Round off to the Nearest Integer).

[Given : Molal elevation constant of water $K_{b} = 0.5 K kg {mol}^{- 1}$ boiling point of pure water $= 100 ° C$ ]

EASY

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The boiling point of

0.001 M

aqueous solutions of

NaCl, {Na}_{2} {SO}_{4}, K_{3} {PO}_{4}

and

{CH}_{3} COOH

should follows the order.

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

A solute $A$ dimerizes in water. The boiling point of a $2$ molal solution of $A$ is $100.52 {}^{\circ}C$ . The percentage association of $A$ is ___ .
(Round off to the Nearest integer)

Use : $K_{b}$ for water $= 0.52 K kg {mol}^{- 1}$

Boiling point of water $= 100 ° C$

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The boiling point of a sugar solution when

3.42 g

of sugar is dissolved in

40 g

water is

(K_{b} = 0.52 {}^{\circ}C)

EASY

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

An aqueous solution containing

1.0 g

of urea boils at

100.25 ° C .

The aqueous solution containing

3.0 g

of glucose in the same volume will boil at:

MEDIUM

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

An aqueous solution freezes at

272.4 K

, while pure water freezes at

273 K

, given

K_{f} = 1.86 K kg {mol}^{- 1}

, and

K_{b} = 0.512 K kg {mol}^{- 1};

the molality of solution and boiling point of solution respectively will be -

EASY

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

1 m o l

N a C l

solute is dissolved in

1 k g

of water, at what temperature will water boil at

1.013

bar?

(K_{b} o f w a t e r i s 0.52 K k g m o l^{- 1})

HARD

Chemistry>Physical Chemistry>Solutions>Elevation of Boiling Point

The plot given below shows $P - T$ curves (where, $P$ is the pressure and $T$ is the temperature) for two solvents $X$ and $Y$ and isomolal solutions of $NaCl$ in these solvents. $NaCl$ completely dissociates in both the solvents.

Question Image

On the addition of equal number of moles of a non-volatile solute $S$ in equal amount (in $kg$ ) of these solvents, the elevation of boiling point of solvent $X$ is three times that of solvent $Y$ . The solute $S$ is known to undergo dimerization in these solvents. If the degree of dimerization is $0.7$ in the solvent $Y$ , the degree of dimerization in the solvent $X$ is _______.

Important Questions on Solutions

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