The substances whose solubility decreases with increase in temperature:

1.  $Ca{\left(OH\right)}_2$

2.  $N{a}_{2}C{O}_3$

3.  $N{a}_{2}S{O}_4$

4.  all of these 

Two solutions ($A$) containing ${\mathrm{FeCl}}_3\left(\mathrm{aq}\right)$ and ($B$) containing ${\mathrm{K}}_4\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]$ are separated by semipermeable membrane as shown below. If ${\mathrm{FeCl}}_3$ on reaction with ${\mathrm{K}}_4\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]$, ​produces blue colour of ${\mathrm{Fe}}_4\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]$, the blue colour will be noticed in:

(1) (A)

(2) (B)

(3) in both (A) and (B)

(4) neither in (A) nor in (B)

Each pair forms ideal solution expect:

(1) ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Br} \mathrm{and} {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{I}$

(2) ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{Cl} \mathrm{and} {\mathrm{C}}_6{\mathrm{H}}_5\mathrm{Br}$

(3) ${\mathrm{C}}_6{\mathrm{H}}_6 \mathrm{and} {\mathrm{C}}_6{\mathrm{H}}_5·{\mathrm{CH}}_3$

(4) ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{I} \mathrm{and} {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

Mole fraction of solute in an aqueous solution that boils at 100.104 is :

( $K_b$ for $H_{2}O$ = 0.52 K $molalit{y}^{-1}$)

1.  0.008

2.  0.004

3.  0.061

4.  0.996

At Abu mountains, water boils at 96$°C$. What amount of NaCl be added in 1 kg water so that it boils at 100$°C$. ${\mathrm{K}}_{\mathrm{b}} \mathrm{for} {\mathrm{H}}_2\mathrm{O} = 0.52 \mathrm{K} {\mathrm{molality}}^{-1}$.

1.  225 g

2.  450 g

3.  200 g

4.  125 g 

Freezing point of an aqueous solution is -0.166$°$C. Elevation of boiling point of same solution would be-

(K_b = 0.512 K m^-1 and K_f = 1.66 K m^-1)

A substance is completely trimerized on dissolution in a solvent. The van;t Hoff factor (i) for such change is:

1.  1

2.  2

3.  3

4.  1/3 

The freezing point of aqueous solution that contains 5% by mass urea, 1.0% by mass KCl and 10% by mass of gulcose is: (k${}_f$H${}_2$=1.86 K molality${}^{-1}$)

1. 290.2 K 

2. 285.5 K 

3. 269.93 K 

4. 250 K 

The boiling point of an azeotropic mixture of water and ethyl alcohol is less than that of the theoretical value of a water and alcohol mixture. Hence, the mixture shows: 

1. That solution is highly saturated

2. Positive deviation from Raoult's law

3. Negative deviation from Raoult's law

4. Nothing can be inferred

A maxima or minima obtained in the temperature, composition curve of a mixture of two liquids indicates:

1.  an azeotropic mixture

2. a eutectic formation

3.  that the liquids are immiscible with one another

4.  that the liquids are partially miscible at hte maximum or minimum