Question

How many joules are needed to change the temperature of 40 g of water from 33 C to 23 C?

Answer 1

Step-by-step explanation:

Given parameters:

Mass of water = 40g

Initial temperature = 33°C

Final temperature = 23°C

Specific heat capacity of water = 4.2J/g°C

Unknown:

Quantity of heat = ?

Solution:

To solve this problem, we use the expression below;

H = m c Δt

H is the quantity of heat

m is the mass

c is the specific heat capacity

Δt is the change in temperature

H = 40 x 4.2 x (23 - 33) = -1680J

The water will have to lose 1680J of heat to bring it to that final temperature.