- Joined
- Jul 16, 2008
- Messages
- 80
- Reaction score
- 0
Maybe someone already asked this or maybe I am asking a stupid question. But I don't get the EK's explaination on why #62 should be C.
Simply speaking, the question said that the standard enthalpy of formation for liquid water is -285.8kJ/mol. It asked which of the following could be the standard enthalpy of formation for water vapor?
A. -480.7kJ/mol
B. -285.8kJ
C. -241.8kJ/mol
D. +224.6kJ/mol
The EK said that the answer should be C because condensation must occur to form liquid water. Since condensation is an exothermic process, the formation of liquid water should be more exothermic than the formation of water vapor. This explanation is logical and seems correct to me. However, if the formation of liquid water is more exothermic than the formation of water vapor, shouldn't choice A be the answer instead of choice C? -241.8kJ/mol is less exothermic than -285.8kJ/mol right?
Simply speaking, the question said that the standard enthalpy of formation for liquid water is -285.8kJ/mol. It asked which of the following could be the standard enthalpy of formation for water vapor?
A. -480.7kJ/mol
B. -285.8kJ
C. -241.8kJ/mol
D. +224.6kJ/mol
The EK said that the answer should be C because condensation must occur to form liquid water. Since condensation is an exothermic process, the formation of liquid water should be more exothermic than the formation of water vapor. This explanation is logical and seems correct to me. However, if the formation of liquid water is more exothermic than the formation of water vapor, shouldn't choice A be the answer instead of choice C? -241.8kJ/mol is less exothermic than -285.8kJ/mol right?
