Question

State the underlying principle on which the method of mixtures is based for the determination of the specific heat capacity of substances.

Answer 1

The method of mixtures is based on the law of conservation of energy. When a hot body is mixed with a cold body in an insulated calorimeter, the heat energy lost by the hot body is equal to the heat energy gained by the cold body, provided no heat is lost to the surroundings.

Mathematically, $$m_1 c_1 (\theta_1 - \theta) = m_2 c_2 (\theta - \theta_2)$$.