Question

You take a 150.485 g piece of copper

and

heat it over a

Bunsen burner. After a few

minutes of heating you place

the

heated

copper into 500 g of water at

25.00

̊C.

After

a

while you measure

the

temperature of

the water and find

that it is 45.32

̊C.

What was

the

temperature of the metal before

you put it in the water? The specific

heat of copper is

0.385

J/(g∙ ̊C).

Assume no energy was lost.

Answer 1

Heat energy absorbed by the water = mass of water x specific heat capacity of water x change in temperature.

= 500 x 4.184 x (45.32-25) = 42509.44 J

This much energy was transferred from Cu to water

42509.44 J = mass of Cu x specific heat capacity of Cu x change in temperature.

42509.44 J = 150.485 x 0.385 x change in temperature

change in temperature = 733.71 degree Celsius.

After heat transfering (equilibrium temperature) is 45.32 degree Celsius

Thus, the initial temperature of Cu = 45.32 + 733.71 = 779.03 degree Celsius.