What amount of heat will be released during the crystallization of 200 grams of water at a temperature of 0 degrees.

In order for water of a certain mass to completely freeze, for example, at a temperature of 0 ° C, it must cool down – to give out a certain amount of thermal energy.

To freeze water weighing 1 kg, 330 kJ must be allocated. This value is called the specific heat of crystallization of water (its transformation into ice, freezing).

In our case, the mass of water is 200 g. To freeze 200 g of water, it will take five times less heat to “take” from it than for 1 kg.

According to the formula Q = λm, where Q is the amount of heat, λ is the specific heat of crystallization (melting), m is the mass – 330 kJ / kg * 0.2 kg = 66 kJ.

Under the conditions of the example, 200 g of water during crystallization will transfer to the outside (for example, to surrounding bodies) an energy of 66 kilojoules.