How many joules of energy are needed to change the temperature of 75.0 g of water 250C?

17000 joules

Explanation:

With knowledge of the specific heat capacity of a substance, its mass, and the temperature change, we can convert this to the energy required for this temperature change using:

ΔH=mCΔT, where

ΔH = change in enthalpy (J)

m = mass of substance being heated (g) i. e. water in this question

C = specific heat capacity (J/g°C)

ΔT = change in temperature (°C)

We know mass = 65g and ΔT=76°C-12°C=64°C

The specific heat capacity of water is 4.18J/g°C

Therefore, ΔH=65g⋅ 4.18J g°C ⋅64 °C

=17388.8J

=17000J (2 significant figures)