Phase Change

Q.

When the ice from a frozen lakes starts to melt, the temperature of the surroundings ______.

1. Increases

2. Decreases

3. Remains same

4. Increases or decreases as it depends on the amount of the ice which gets melted

Q.

The boiling point of the water is defined as:

1. None of these

2. The constant temperature at which water changes to steam

3. The constant pressure at which water changes to steam

4. The constant volume at which water changes to steam

Q. Calculate the amount of heat required to convert 1.00 kg of ice at $-{10}^{\circ }$C into steam at ${100}^{\circ }$C at normal pressure. $(S_{ice}=2100Jk{g}^{-1}{K}^{-1},$
$S_{water}=4200Jk{g}^{-1}{K}^{-1},$
$L_{f,ice}=3.36\times {10}^{5}Jk{g}^{-1}$,
$L_{v,water}=2.25\times {10}^{6}Jk{g}^{-1})$

1. $6.03\times {10}^{6}J$

2. $3.03\times {10}^{6}J$

3. $4.03\times {10}^{6}J$

4. $5.03\times {10}^{6}J$

Q.

Which among these contract on melting?

1. Lead

2. Wax

3. Ice

4. Iron

Q. A lump of ice (0.1 kg) at $-{10}^{\circ }$C is put in 0.15 kg of water at ${20}^{\circ }$C. How much water will be found in the mixture when it has reached thermal equilibrium?
$(C_{ice}=0.5kcalk{g}^{-1}{k}^{-1},L_{ice}=80kcalk{g}^{-1})$

1. 150 g
2. 31.25 g
3. 181.25 g
4. 210 g

Q.

For a pure substance, boiling point and condensation point are the same.

1. True

2. False

Q. When the solid changes into a liquid, there is no change in:

1. Temperature
2. Average kinetic energy of the molecules
3. Intermolecular force of attraction
4. Average distance between the molecules

Q. When ice melts into water at $0^{\circ }\text{C}$, its volume will

1. remain the same
2. increase significantly
3. decrease
4. increase slightly

Q.

The constant temperature at which solid changes to a liquid called as___point.

Q. The constant temperature at which solid changes to a liquid is called as ___ point.

1. boiling
2. melting
3. freezing
4. vaporization