Thermodynamics

First, we need to find out how many moles of water we have.
n‌=‌

m

M

=‌

180

18

‌=10mol
∆T‌=T2−T1=15−10=5K
The energy needed to heat the water is given by the formula: Q=nCp∆T
Here, n is number of moles (10), Cp is the specific heat (75.3Jmol−1K−1), and ∆T is the temperature change (5 K).
So, Q=10×75.3×5=3765J