A mass of a liquid at 30oC is mixed with a mass of the same liquid at 70oC and the temperature of the mixture is 45oC. Find the ratio of the mass of the col...

A mass of a liquid at 30oC is mixed with a mass of the same liquid at 70oC and the temperature of the mixture is 45oC. Find the ratio of the mass of the cold liquid to the mass of the other liquid.

Answer Details

We can solve this problem using the principle of mixtures. Let's assume that the masses of the cold and hot liquids are m1 and m2, respectively, and their specific heat capacities are the same. The temperature change of the cold liquid is (45-30)=15°C, and that of the hot liquid is (70-45)=25°C. Now, using the principle of mixtures, the total heat lost by the hot liquid = the total heat gained by the cold liquid, that is: m1*15 = m2*25 Simplifying the above equation, we get: m1/m2 = 25/15 = 5/3 Therefore, the ratio of the mass of the cold liquid to the mass of the other liquid is 5 : 3. So, is the correct answer.