Question

How much thermal energy is released when 500 g of steam at 100 degrees celsius condenses into liquid and then cools to 50 degrees celsius.

What I`ve Attempted:
Q=mLv
m = 500g (0.5 kg)
Lv = 2.3*10^6

Q=(0.5)(2.3*10^6)
Q=1,150,000 J
Q = 1.2*10^6

The answer in the back of the book is 1.3*10^6. Am I overlooking something with the temperatures?

Answer 1

I answered this once. You are correct, it is a matter of rounding and significant figures.