This is basic chemistry that you shouldn't be getting wrong.
The average bond energy of H-O in water is 464 kJ/mol at STP
The average bond energy of C=0 in CO2 is 804 kJ/mol at STP.
CO2 bond strength is about double that of water because C has a double bond to each O due to C's valence of 4. Water only has a single bond between atoms.
