Latent Heat of Fusion

Q.

When a solid melts its temperature remains constaint. Give reason

Q.

Why is ice at 273 K more effective in cooling than water at the same temperature?

Q.

Why does the temperature remain constant during the melting of ice even though heat is supplied continuously ?

Q. When a solid melts, its temperature remains the same.so where does the heat energy go

Q.

Why is heat energy needed to melt a solid? What is this heat energy called?

Q.

Why is ice at 273k is more effective in cooling than water at same temperature?

Q.

Define Fusion

Q. Question 3
For any substance, why does the temperature remain constant during the change of state?

Q.

Explain why, ice at $0^{\circ }$C is more effective in cooling than water at the same temperature.

Q.

Which contains more heat, 1 Kg of ice at $0^{\circ }$C or 1 Kg of water at $0^{\circ }$C? Give reson for your answer.

Q.

What do you understand by the term 'latent heat' ?What are the two types of latent heat ?

Q.

Which of the following energy is absorbed during the change of state of a substance?

(a) specific heat (b) latent heat (c) heat capacity (d) heat of solution

Q.

1. Process of boiling takes longer time than the process of melting.

2. All the options are correct.

3. Ice takes time to heat up to 0°C.

4. During melting and boiling temperature does not rise.

Q. Define the latent heat of fusion.

Q.

(a)Conversion of solid to vapour is called sublimation. Name the term used to denote the conversion of vapour to solid.

(b)Conversion of solid state to liquid state is called fusion;what is meant by latent heat of fusion?

Q.

What is the SI unit of latent heat of fusion?

Q.

The latent heat of fusion of ice is:

(a) 33.4 $\times {10}^{5}J/Kg$ (b) 22.5 $\times {10}^{5}J/Kg$
(c) 33.4 $\times {10}^{4}J/Kg$ (d) 2.25 $\times {10}^{4}J/Kg$

Q.

Latent heat of fusion is the amount of heat energy required to change:

1. kg of liquid into its gaseous state at its boiling point

2. 1 kg of solid into its liquid state at its melting point

3. 1 kg of liquid into its solid state at its freezing point

4. 1 kg of solid into its gaseous state at its boiling point

Q. Give the reason for the following:
(a) Ice at 0 degree C appears to be colder in the mouth than water at 0 degree C.

Q.

When heat is constantly supplied by a gas burner with a small flame to melt ice, then the temperature of ice during melting :

(a) increases very slowly (b) does not increase at all

(c) first remains constant and then increases (d) increases to form liquid water

Q.

What happens to the heat energy supplied to a solid once it starts melting ?

Q.

Which has more latent heat - ice or water?

Q. Question 12
A student heats a beaker containing ice and water. He measures the temperature of of the content of the beaker as a function of time. Which of the following (Fig. 1.1) would correctly represent the result? Justify your choice.

Q. Which of the given options causes the temperature of a substance to remain constant while it is undergoing a phase change?

1. 
   Latent heat
2. 
   Lattice energy
3. 
   Ionization energy
4. 
   None of these

Q.

Give reason why?

On heating a sublimeable solid, the molecule break free & escape from the surface of solid directly into vapour.

Q.

Heat energy can cause change of state for a given substance.

1. True
2. False

Q.

Soft drinks are cooled by adding ice cubes.

Q. How does ice get converted into water?

1. Heat is absorbed.

2. Heat is released.

3. Temperature increases.

4. Temperature decreases.

Q.

Can you measure latent heat with a thermometer$?$

Q. Define the following:
(a) Specific latent heat of fusion
(b) Specific latent heat of vaporisation