Boiling

Q. $1.22g$ of an organic acid is separately dissolved in $100g$ of benzene $(K_b=2.6Kkgmo{1}^{-1})and100g$ of acetone $(K_b=1.7Kkgmo{1}^{-1})$. The acid is known to dimerize in benzene but remain as a monomer in acetone. The boiling point of the solution in acetone increases by $0.17°C$. The increase in boiling point of solution in benzene in $°Cisx\times {10}^{-2}$. The value of $x$ is _____________. (Nearest integer)
(Atomic mass : $C=12.0,H=1.0,O=16.01]$

Q.

What is the boiling point of water?

Q.

At high altitudes, why do liquids boil at a lower temperature?

Q.

The boiling point of NH3 H2O and HF are exceptionally higher explain

Q.

Among the following the least thermally stable is-

1. K₂CO₃

2. Na₂CO₃

3. BaCO₃

4. Li₂CO₃

Q. The distillation technique most suited for separating glycerol from spent-lye in the soap industry is:

1. Fractional distillation
2. Steam distillation
3. Distillation under reduced pressure
4. Simple distillation

Q.

How will you confirm that a colorless liquid given is pure water?

Q.

which type of attractive force is present between the polar and non polar molecule

Q. The vapour pressure of pure liquids A and B are 450 & 700 mmHg respectively at 350 k . Find out the composition of liquid mixture if total pressure is 600 mmHg .Also find the composition of the vapour phas

Q.

What is the basic principle behind simple distillation process?

Q. At higher altitude:

1. Boiling point of liquid increases
2. Boiling point of liquid decreases
3. Boiling point of liquid remains unaffected
4. Melting point of solid increases

Q. The distillation technique most suited for separating glycerol from spent-lye in the soap industry is:

1. Steam distillation
2. Distillation under reduced pressure
3. Fractional distillation
4. Simple distillation

Q. Atmospheric pressures recorded in different cities are as follows :
$\begin{array}{ccccc}\text{Cities}& \text{Shimla}& \text{Bangalore}& \text{Delhi}& \text{Mumbai}\\ p{\text{in N/m}}^2& 1.01\times {10}^5& 1.2\times {10}^5& 1.02\times {10}^5& 1.21\times {10}^5\end{array}$
Consider the above data and mark the place at which liquid will boil first.

1. Shimla
2. Bangalore
3. Delhi
4. Mumbai

Q. why H20 a liquid and H2S a gas

Q. Sarath is heating water in a closed container. He wants to boil the water. But he is wondering whether the water will boil or not. Can you help him? Will water boil in that closed container?

1. Yes
2. No

Q.

What are two measures of liquidity?

Q.

The variation of vapour pressure of different liquids with temperature is shown in fugure

(i) Calculate graphically boiling points of liquids A and B.

(ii) If we take liquid C in a closed vessel and heat it continuously. At what temperature will it boil?

(iii) At high altitude, atmospheric pressure is low (say 60 mm Hg). At what temperature liquid D boils?

(iv) Pressure coojer is used for cooking food at hill station. Explain in terms of vapour pressure why is it so?

Q.

A person living in Shimla observed that cooking food without using pressure cooker takes more time. The reason for this observation is that at high altitude

(a) pressure increases (b) temperature decreases

(c) pressure decreases (d) temperature increases

Q. Which of the following is true for a binary solution consisting of immiscible liquids?

1. The total vapour pressure is the difference of the separate vapour pressures of the two components in the pure state at the given temperature
2. The total vapour pressure is the sum of the separate vapour pressures of the two components in the pure state at the given temperature.
3. The total vapour pressure is the product of the separate vapour pressures of the two components in the pure state at the given temperature
4. None of the above

Q. 1. A mixture is chlorobenzene and water (which are virtually immiscible) boils at 90.3^° C at an external pressure of 740.2mm. The vapour pressure of pure water at 40.3^° C if 530.1mm. What is the percentage weight of cholrobenzene?

Q. Boiling occurs spontaneously at all temperatures.

1. True
2. False

Q.

Why are the low boiling liquids called volatile liquids?

Q. The boiling point of a solution of $0.512\text{gm}$ of napthalene, $C_{10}{H}_8,$ in $24\text{gm}$ of chloroform is ${0.5}^{\circ }\text{C}$ higher than that of pure chloroform. The molal boiling point elevation constant of chloroform is (in K-kg/mol)

Q.

How can we know, which molecule is polar and which is non polar molecule?

Q. Sea water is found to contains 5.85% $NaCl$ and 9.50% $MgC{l}_2$ by weight of solution. Calculate its normal boiling point assuming 80% ionisation for $NaCl$ and 50% ionisation of $MgC{l}_2\left[K_b\right(H_{2}O)=0.5kgmo{l}^{-1}K]$

1. $T_b=101.3K$
2. $T_b=102.{24}^{\circ }C$
3. $T_b=112K$
4. $T_b={110}^{\circ }C$

Q. Which is the most volatile?

Q. Which of the following molecules does not possess a permanent dipole moment :
(1) H2S
(2) SO2
(3) S(O3)2-
(4) CS2

Q.

Statement given below is incorrect. Write the correct statement:

At boiling point, the substance occurs into both solid and liquid state.

Q. Vapour pressure of pure water is 40 mmHg. If a non volatile, non electrolyte solute is added to it vapour pressure is reduced by 4 mmHg. Find the molality of the solution.

Q.

When tungsten put in the volcano, it will melt or not