"Calculate the enthalpy of vaporization of water given that, when 5.00 grams of steam (gaseous H2O) at 100°C was introduced into a beaker containing 500 grams of water at 20.0°C, the temperature rose to 26.2°C."

Question

H2O (l) -> H2O (g)
ΔH = ΔH_vap

5g H2O (g) @ 100°C
500g H2O (l) @ 20°C
Final temperature is 26.2°C

Is ΔH_vap 40.7 kJ/mol have to be used or we're finding that?

Answer 1

http://www.jiskha.com/display.cgi?id=1473202007