Question

How much heat is released when 150. g of iron cools from 525°C to 100°C? (Cp = 0.44 J/gºC) A 50.0 g block of glass (Cp = 0.50 J/gºC) absorbs 333 joules of heat energy. How much does the temperature of the glass rise? The temperature of a silver coin (Cp = 0.24 3/9°C) falls by 353 °C as it releases 5,550 Joules of heat. What is the mass of the coin 5.

Answer 1

3)

Given:

m = 150 g

C = 0.44 J/g.oC

Ti = 525 oC

Tf = 100 oC

use:

Q = m*C*(Tf-Ti)

Q = 150.0*0.44*(100.0-525.0)

Q = -28050 J

Negative sign shows that heat has been released.

Answer: 28050 J

4)

Given:

Q = 333 J

m = 50 g

C = 0.5 J/g.oC

use:

Q = m*C*(delta T)

333 = 50.0*0.5*delta T

delta T = 13.32 oC

delta T = 13.32 oC

Answer: 13.3 oC

5)

Given:

Q = -5550 J

C = 0.24 J/g.oC

Ti = 0 oC

Tf = -353 oC

use:

Q = m*C*delta T

-5550 = m*0.24*(-353)

m = 65.5 g

Answer: 65.5 g