A 45.0 beaker of water cools from 67.0°C to 45.0°C. How many joules of
heat are released?

4142.16J

Explanation:

Given parameters:

Mass of water in the beaker  = 45g

Initial temperature  = 67°C

Final temperature  = 45°C

Unknown:

Quantity of heat released  = ?

Solution:

To solve this problem, we use the expression below:

       H  = m cФ

H is the quantity of heat

m is the mass

c is the specific heat  = 4.184J/g°C

Ф is the change in temperature

      H  = 45 x 4.184 x (45  - 67) = 4142.16J

The amount of heat released is 4142.16J