# Problem: Calculate ΔHrxn for the following reaction: CaO(s) + CO2(g) → CaCO3(s)Use the following reactions and given ΔH’s:Ca(s) + CO2(g) + 1/2 O2(g) → CaCO3(s); ΔH = –812.8 kJ2 Ca(s) + O2(g) → 2 CaO(s); ΔH = –1269.8 kJ

###### FREE Expert Solution

We are asked to find ΔHrxn for the following reaction: CaO(s) + CO2(g) → CaCO3(s)

Modify the equation in such way that it adds up to be the target reaction.

Reaction                                                                                                Modification

Ca(s) + CO2(g) +1/2 O2(g)  → CaCO3(s)                                                 Eqn1   [no change]
CaO(s) →   Ca(s) +1/2 O2(g)                                     -(1/2)Eqn2   [reversed and multiplied by 1/2]

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CaO(s) + CO2(g) → CaCO3(s)

Ca(s) + CO2(g) + 1/2 O2(g) → CaCO3(s); ΔH = –812.8 kJ
2 Ca(s) + O2(g) → 2 CaO(s); ΔH = –1269.8 kJ

###### Problem Details

Calculate ΔHrxn for the following reaction: CaO(s) + CO2(g) → CaCO3(s)

Use the following reactions and given ΔH’s:
Ca(s) + CO2(g) + 1/2 O2(g) → CaCO3(s); ΔH = –812.8 kJ
2 Ca(s) + O2(g) → 2 CaO(s); ΔH = –1269.8 kJ