Question

50 g Cu (c=24.5J/K/mol) is heated to 100C and then placed in 250g water(c=4.184J/g/K) at 0C. What is the final temperature of water (in C)?

Answer 1

we know that the heat gained by water will be the heat lost by the metal.

The heat lost by metal = mole of metal X heat capacity of metal X change in temperature

Mass of copper = 50g

Atomi weight = 63.5

So moles = Mass ./ atomic weight = 50 / 63.5 = 0.79

Heat lost by metal = 0.79 X 24.5 X (final temperarure - 100)

Heat gained by water = mass of water X heat capacity of water X change in temperature

Heat gained by water = 250 X 4.184 X (final temperatre - intial temperature) = 250 X 4.184 X (final temperature - 0)

0.79 X 24.5 X (T2-100) = 250 X 4.184 X (T2-0)

1936 - 19.36 X T2 = 1046 T2

890 = 19.36T2

T2 = 45.97

so the final temperature = 45.97 ⁰C