The amount of heat required for a substance to change from one state to another without change in temperature is called:

The correct answer is Latent Heat.

Concept:

• Latent Heat - It is the heat required to convert a solid into a liquid or vapour, or a liquid into a vapour, without a change of temperature.
• English scientific expert Joseph Black presented the idea of latent heat.

Important Points

• The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. 
• The specific heat of water is 1 calorie/gram °C = 4.186 joule/gram °C, which is higher than many other common substances.