Question

How much heat is evolved when 1258 g of water condenses to a liquid at 100.°C?

Answer 1

see below

Answer 2

The molar mass of water is 18.0 g/mol. 1255 g H2O x (1 mol / 18.0 g) = 69.7 mol H2O 69.7 mol H2O x (- 40.7 kJ/mol) = - 2840 kJ The negative sign shows that heat is given off.

Answer 3

-12.66