Equal masses of paraffin and water are mixed in a container of negligible thermal capacity. Initial temperature of water is 80C and that of paraffin is 20 0C. The final temperature of mixture is:

Explanation

Since the container has negligible thermal capacity, the heat lost by the hot water (80°C) will be equal to the heat gained by the cold paraffin (20°C). The heat exchange can be calculated using the principle of calorimetry:m₁ * c₁ * (Tf - T₁) = m₂ * c₂ * (T₂ - Tf)where:m₁ = mass of waterc₁ = specific heat capacity of waterTf = final temperature of the mixtureT₁ = initial temperature of waterm₂ = mass of paraffinc₂ = specific heat capacity of paraffinT₂ = initial temperature of paraffinSince the masses of paraffin and water are equal, m₁ = m₂. Also, since the container is negligible in thermal capacity, c₁ ≈ c₂.Using this information, we get:m * c * (Tf - 80) = m * c * (20 - Tf)Tf - 80 = 20 - Tf2 * Tf = 100Tf = 50°C