Question

Use standard heats of formation in Appendix L to calculate standard enthalpy changes for the following reactions.

1.45 x 10-2 mol of carbon is oxidized to CO2(g)

Please help me!

Answer 1

Look up the heat of formation for CO2 in the table provided to you. My table has something like 393.5 kJ/mol. That reaction is for
C + O2 ==> CO2
delta H reaction is (n*deltaHf products) - (n*deltaHf reactants) =
(n*deltaHf CO2) - [(n*deltaHf C) + (n*deltaHf O2)]
delta Hrxn = -393.5 -(+0) = -393.5 kJ/mol.
You have 1.45E-2 mol instead of 1 mole; therefore, delta H rxn = -393.5 kJ/mol x 1.45E-2 mol = ?? kJ.

Answer 2

Thank you! but does n in (n*deltaHf products) - (n*deltaHf reactants) mean amount? What amount is it talkinging about?