Energy changes
Read our general notes on Risk Assessment
Does an oxygen molecule (O2) have a standard enthalpy change of formation? If so what is it? I thought that one of the definitions of an element was that it had no enthalpy change of formation... Thanks
Corrie writes ...
You are absolutely correct - the standard enthalpy change of formation of 1 mol of O2(g) is defined, as for all elements in their normal states at standard conditions, as zero.
So the standard enthalpy change of formation of I2(s) is also zero, whereas the standard enthalpy change of formation of I2(g) is + 62.4 kJ mol-1.
Rate this page or react
Share your views on this page, 2 ratings so far
3
, rated at 
updated: 09 September 2007
