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From the EK 1001 Chemistry (Q 375), it says that the heat of formation of water vapor is negative (and that it is less negative than the heat of formation of liquid water).
I do not understand this one bit. I thought that when you are going from liquid to gas, you are putting in energy to weaken the bonds (thus an endothermic process), and an endothermic process means a positive heat of formation, not a negative heat of formation. Also, how would it be less negative than the heat of formation of liquid water (which I thought would be more negative (exothermic) since you are going from gas to liquid)...
Can anybody help me understand this? From the back of the book, it also says that the heat of formation of water vapor is essentially the heat of combustion of hydrogen gas - a very exothermic process. How are those two even the same? Hellllllp
I do not understand this one bit. I thought that when you are going from liquid to gas, you are putting in energy to weaken the bonds (thus an endothermic process), and an endothermic process means a positive heat of formation, not a negative heat of formation. Also, how would it be less negative than the heat of formation of liquid water (which I thought would be more negative (exothermic) since you are going from gas to liquid)...
Can anybody help me understand this? From the back of the book, it also says that the heat of formation of water vapor is essentially the heat of combustion of hydrogen gas - a very exothermic process. How are those two even the same? Hellllllp