A water heater warms 2.4 kg of water from a temperature of 7.0°C to 68.4°C. Determine the amount of energy required for this increase in temperature. Water has a specific heat of 4.18 J/g*°C.

Question

Determine the amount of energy required for the increase in temperature

Answer 1

Use the following equation where heat(q) is equal to mass(m) times specific heat of a substance(C) times change in temperature(ΔT):

q = m x C x ΔT

q = 2.4 kg = 2400 g

C = 4.18 J/g°C

ΔT = 68.4 - 7 = 61.4

q = 2400 g x 4.18 J/g°C x 61.4 °C = 6.15 x 10⁵ J

The heat in this example is positive indicating heat is being added to the water.