Please help?

1 ⤊

What is the Delta H_rxn for the following reaction:

CaO(s) +CO_2(g)---->CaCO_3(s)

Use the following reactions and given Delta H

Ca(s) +CO_2(g) +1/2 O_2(g)-----> CaCO_3(s)

Delta H= -812.8 KJ

2Ca(s) + O_2(g)----> 2CaO(s) Delta H= -1269.8 KJ

2007-10-15 05:51:04 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry

2 answers

Ca (s) + CO2 (g) + 1/2 O2 (g) --> CaCO3 (s) ∆H˚ = -812.8 kJ
CaO (s) --> Ca (s) + 1/2 O2 (g) ∆H˚ = +1269.8 kJ/2 = +634.9

So for CaO (s) + CO2 (g) --> CaCO3 (s), ∆H˚ = -812.9 + 634.9 = -177.9 kJ

2007-10-15 05:57:29 · answer #1 · answered by William Q 5 · 1⤊ 0⤋

634.9-812.8 = -177.9 kJ

2007-10-15 06:08:45 · answer #2 · answered by ag_iitkgp 7 · 0⤊ 0⤋