00:01
A substance which will have a delta h standard of formation of zero is going to be a pure substance under standard conditions.
00:19
And specifically, the substance needs to be an element in its standard state.
00:30
Only elements in their standard state have delta h's of formation of zero.
00:35
So, i don't know whether this was meant to be a trick question or not, but iron, oxygen, chlorine, all three of these are elements in their standard state.
00:55
The standard state of, well actually, iron, probably not, because iron at 1200 degrees celsius is going to be a liquid.
01:09
And the standard state for iron is what it is at 25 degrees celsius and one atmosphere, which is a solid...