Latent Heat

Q.

define latent heat of fusion

Q.

Explain why there is no rise in temperature of a substance when it undergoes a change of state through heat is supplied continuously.

Q.

Define solidification.

Q.

1.Define latent heat of fusion

2.Define latent heat of vapourisation

Q. Latent heat of vaporization of water is more than latent heat of fusion of ice.

1. False
2. True

Q.

The amount of water vapour present in the air is called?

1. Temperature

2. Humidity

3. Moisture

Q. The amount of heat energy required to change 1 kg of solid into liquid at its melting point is known as_________.

1. latent heat of condensation
2. latent heat of fusion
3. latent heat of vaporisation
4. latent heat of sublimation

Q.

The energy absorbed or released when a substance changes its physical state can be termed as_________.

1. specific heat capacity

2. latent heat

3. heat of sublimation

4. evaporation heat

Q.

Latent heat of fusion and vaporization

Q.

Give the usual name for the following:

Heat required to change the state of a substance without changing the temperature.

Q.

Explain the process of sublimation in terms of kinetic theory.

Q. Explain Charles's law on the basis of the kinetic theory of matter.​

Q.

Heat energy required to melt $10kg$ ice at its melting point will be _____. (The latent heat of fusion of water = $333.55kJk{g}^{-1}$).

1. $2.33\times {10}^{6}J$

2. $3.33\times {10}^{6}J$

3. $4.33\times {10}^{4}J$

4. $4.33\times {10}^{5}J$

Q.

5. the process of conversion of solid into liquid

Q.

The process due to which an ice cube melts into water is known as………..

Q.

Why does our hand feel cold when we pour some spirit on it?

Q.

Latent heat of evaporation of two liquids A and B is 100 J/Kg and 150 J/Kg respectively. Which can produce more cooling effect and why?

Q.

Why do rivers and lakes not freeze easily ?

Q.

For any situation why does the temperature remain constant during the change of state

Q.

Explain why:

(a) Boiled or distilled water taste flat.

(b) Ice at $0^{\circ }C.$ has the greater cooling effect than water at $0^{\circ }C.$

(c) Burns caused by steam are more severe than burns caused by boiling water.

(d) Rainwater does not leave behind concentric rings when boiled.

(e) Air dissolved in water contains a higher proportion of oxygen.

(f) If distilled water is kept in a sealed bottle for a long time, it leaves etchings on the surface of the glass.

Q.

On heating, _______ changes into carbon dioxide gas without becoming liquid.

Q.

Draw a neat diagram of temperature versus time when a substance is heated from $0^{o}C$ to ${80}^{o}C$. Along with this, also draw another curve when the molten substance cools to room temperature. How will you find the melting and freezing point from the graphs drawn?

Q.

Abstract noun of hate, mix, poor, ignore, clean, believe, suspicious is?

Q.

Explain what you understand from the following diagram:

Q. If $120g$ steam of temperature $100{}^{\circ }C$ is released on an ice slab of temperature $0{}^{\circ }C$, how much ice will melt?
(Latent heat of melting of ice = $80cal/g$
Latent heat of vapourization of water = $540cal/g$)

1. $691g$
2. $960g$
3. $265g$
4. $625g$

Q. Identify A, B, C and D: first one is done for you.

Q.

Which will cause more severe burns, steam or water at the same temperature ?

Q.

Explain the concept of an iceberg.

Q.

why is latent heat of vapourization higher than latent heat of fusion?

Q. How does perspiration, coolers, earthen pots, cotton clothes and spirit on hand display cooling effect of evaporation?