Which equation is a correctly written thermochemical equation?
Responses

Fe (s) + O2 (g)→Fe2O3 (s), ΔH= −3,926 kJ

uppercase F lowercase e left parenthesis lowercase s right parenthesis plus uppercase O subscript 2 end subscript left parenthesis lowercase g right parenthesis rightwards arrow uppercase F lowercase e subscript 2 end subscript uppercase O subscript 3 end subscript left parenthesis lowercase s right parenthesis , delta uppercase H equals negative 3,926 lowercase k uppercase J,

C3H8 (g) + 5O2 (g)→3CO2 (g) + 4H2O (l), ΔH= −2,220 kJ/mol

uppercase C subscript 3 end subscript uppercase H subscript 8 end subscript left parenthesis lowercase g right parenthesis plus 5 uppercase O subscript 2 end subscript left parenthesis lowercase g right parenthesis rightwards arrow 3 uppercase C O subscript 2 end subscript left parenthesis lowercase g right parentthesis plus 4 uppercase H subscript 2 end subscript uppercase O left parenthesis lowercase l right parenthesis , delta uppercase H equals negative 2,220 lowercase k uppercase J slash lowercase m o l,

2C8H18 + 25O2→16CO2 + 18H2O, ΔH= −5,471 kJ/mol

2 uppercase C subscript 8 end subscript uppercase H subscript 18 end subscript plus 25 uppercase O subscript 2 end subscript rightwards arrow 16 uppercase C O subscript 2 end subscript plus 18 uppercase H subscript 2 end subscript uppercase O , delta uppercase H equals negative 5,471 lowercase k uppercase J slash lowercase m o l,

NH4Cl→NH4 + +  Cl−