Question

If you want to raise the temperature of 200 grams of water at 20 Celsius to 30 Celsius how much water and at what temperature would you need

Answer 1

Heat gained or released in a system can be calculated by multiplying the given mass to the specific heat capacity of the substance and the temperature difference. It is expressed as follows:

Heat = mC(T2-T1) 

When two objects are in contact, it should be that the heat lost is equal to what is gained by the other. From this, we can calculate things. We do as follows:

Heat gained by the system = mC(T2-T1)
Heat gained by the system = (200 g)  (4.18) (30 - 20)
Heat gained by the system = 8360 J
Heat gained = Heat lost
 8360  = - mC(T2-T1) 
 8360  = m (4.18) (30 - T)
2000 = m (30 - T)

Since the problem above is not complete, we cannot really arrive to a definite value of mass and temperature. So, any value of mass and temperature would be the correct answer as long as it agrees the expression 2000 = m (30 - T).