Answer:
To change ice of -20°C to water of 100°C you will need energy of 7524 J.
Explanation:
let q be the heat energy required for that given temperature change, c = 4.18 J/g.°C be the specific heat of water and ΔT be the change in temperature.
then:
the amount of energy required to change ice of temperature -20°C to water at 100°C is:
q = m×c×ΔT
= (15)×(4.18)×(100-(-20))
= 7524 J
Therefore, to change ice of -20°C to water of 100°C you will need energy of 7524 J.
