Question

What is the heat of formation of Benzoic acid?I have asked this question before but made a mistake in my question. The molar enthalpy of combustion for benzoic acid is -3226.6 kJ/mol. The thermochemicasl equation is: 2C6H5COOH (l) + 15O2 -> 6H2O (l) + 14CO2 (g)ΔH= -3226.6 kJ/mol
Given the heats of formation for liquid water is -285.5 kJ/mol and carbon dioxide is -393.5 kJ/mol, calculate the heat of formation of benzoic acid.Please show all proper units because that is where I got mixed up (how do I change -3226.6 kJ/mol into kJ to be used in the standard heats of formation to find x?)

Accepted Answer

First we try to arrange the given value for the enthalpy of formation of water and Carbon dioxide.
H2 (g) + 1/2 O2 (g)  --> H2O (l)      ΔH = -285.5
C(s) + O2 (g) --> CO2 (g)              ΔH = -393.5
and we rewrite the heat of combustion of benzoic acid
2C6H5COOH (l) + 15O2 -> 6H2O (l) + 14CO2 (g)ΔH= -3226.6 kJ/mol
 
6H2O (l) +14CO2 ---> 2C6H5COOH + 15O2 (g)  3226.6kJ/mol
14C(s) + 14O2 (g) ---> 14CO2 (g)                    -5509 kJ/mol
2H2(g) + O2 (s) ----> 2H2O (l)                         -571 kJ/mol
----------------------------------------------------------
4H2O + 14C + 2H2 ---> 2C6H5COOH             -2853.4 kJ/mol

Science

Expert Answers

Unlock This Answer Now

Related Questions

Find the standard enthalpy of formation of ethylene, C2H4(g), given the following data: C2H4(g) + 3O2(g) --> 2CO2(g) + 2H2O(l) H°rxn = –1411 kJ Given that: H°f[CO2(g)] = –393.5 kJ/mol...

What is using these equations below calculate the enthalpy for the reaction : 2H2 (g) + O2 (g) -> 2H2O (g) ΔH = ?1. 2O (g) -> O2 (g) ΔH= -294 kj/mol 2. H2O (l) -> H2O...

How do I balance this equation? C6H5COOH (l) -> H2O (l) + CO2 (g)Liquid benzoic acid (with applied heat) turns into water and carbon dioxide.

Given the following bond enthalpy values, calculate the enthalpy of formation for gas phase isopronanol, C3H7OH at 25 degrees BE (C-C)= 336 kJ mol-1 BE (C-H)= 4.20x10^2 kJ mol-1 BE(C-O)=342 kJ...

The heat of formation of N2O from N2 and O2 is 68 kJ. The heat of formation of NO2 from NO and O2 is -131 kJ. What is the heat of formation of NO from N2 and O2