Change in State

Q. When the ice of a frozen lake starts to melt, the temperature of the surroundings ____.

1. Increases

2. Decreases

3. remains same
4. increases and then decreases

Q. How much heat must be absorbed by ice of mass m = 1000 g at -10 ˚C to take it to liquid state at 15 ˚C?​
${\text{c}}_{\text{ice}}$ = 2220 $Jk{g}^{-1}{K}^{-1}$ ​
${\text{c}}_{\text{liq}}$ = 4190 $Jk{g}^{-1}{K}^{-1}$
$L_F=333$$kJk{g}^{-1}$

1. 418 kJ
2. 300 kJ
3. 318 kJ
4. 400 kJ

Q.

The boiling point of liquid increases by addition of impurities to it.

1. True

2. False

Q. A graph of temperature vs time is shown for a substance being constantly heated from $T_1$ to $T_2$. Which parts of the graph show the substance existing in two states of matter?​

1. AB and CD
2. CD and DE
3. OA and CD​
4. OA and BC​

Q. The melting point of a substance which contracts on melting (like ice) decreases within pressure.

1. increase
2. decrease
3. zero change

Q.

A, B, C and D are volatile liquids. The order of volatility is A > C > B > D. Now, at a particular temperature:

1. Vapour pressure of A > Vapour Pressure of D
2. Vapour pressure of C > Vapour pressure of B
3. Vapour pressure of B < Vapour pressure of D
4. Vapour pressure of A > Vapour pressure of B

Q.

Explain heat in terms of energy.

Q.

The boiling point of liquid increases with ___in pressure.

Q.

What is the temperature of mixture formed when 5 g of ice at 0⁰C is placed in 200 g of water at 10⁰C in a copper calorimeter of heat capacity 25 J/ ⁰C?

1. 3.8^oC

2. 7.8^oC

3. 4.2^oC

4. 2.5^oC

5. 8.7^oC

Q. when vapour pressure increase, boiling point decreases?

Q.

The temperature of the surroundings start falling when the ice of a frozen lake starts melting

1. As ice liberates small amount of heat on melting

2. As ice absorbs small amount of heat on melting

3. As ice absorbs large amount of heat on melting

4. As ice liberates large amount of heat on melting

Q.

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

1. Decreases

2. Remains same

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

4. Increases

Q. When vapour condenses into a liquid:

1. It absorbs heat
2. It liberates heat
3. Its temperature decreases
4. Its temperature increases

Q. When there is a phase change, the temperature of the substance .

1. increases
2. decreases
3. remains the same

Q.

The boiling point of a liquid____by the addition of impurities to it.

1. Decreases

2. Increases or decreases

3. Increases

4. Remains same

Q.

During the phase change, the temperature of the substance_____.

1. Increases

2. Decreases

3. Remains same

4. Cannot be determined

Q.

When vapour condenses into liquid:

1. It absorbs heat.

2. It releases heat.

3. It can either release or absorb heat.

4. No heat exchange occurs.

Q.

During change of state, the temperature

1. remains constant

2. increases

3. decreases

4. may increase or decrease

Q.

What happens to heat supplied to a substance when heat is supplied causes no change in temperature of a substance.