Question

If the theoretical enthalpy of a reaction is -602 KJ/mol and the actual enthalpy determined is -582, what is the percent error??

Answer 1

I've seen this done two ways.

|602 - 582| = 20 as the absolute value.
Then (20/582)*100 = % error = 3.4%
Then I've seen %error =100* (exp value - accepted value)/accepted value and carry the sign forward. Personally I like the first one but critics say this doesn't tell if the error is above or below the accepted value.