In: Chemistry
Ca(s)+2H(aq)--> Ca^2+(aq)+H2 ∆H= -543 KJ/mol
CaCO3(s)+2H(aq)-->Ca^2+(aq)+CO2(g)+H2O(l) ∆H= -15 KJ/mol
Look up the heats formation for CO2 and H2O in the thermodynamic tables and use this information along with the above heats of reaction to calculate the standard enthalpy of formation for CaCO3. Write the balanced equations for the two heat of formations reactions, and use Hess Law in order to answer this question.
C(s) + O2 (g) ------------> CO2(g) ∆H = -393.5Kj/mole
H2 + 1/2 O2(g) ----------> H2O (l) ∆H = -286 Kj/mole
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C(s) + H2(g)+ 3/2 O2(g) -------------> CO2(g) + H2O(l) ∆H = -679.5KJ/mole
C(s)+ H2(g) + 3/2 O2(g) -------------> CO2(g) + H2O(l) ∆H = -679.5KJ/mole
Ca(s)+2H(aq)--> Ca^2+(aq)+H2 ∆H= -543 KJ/mol
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Ca(s) + C(s) +2H(aq) + 3/2 O2(g) -------------> Ca^2+ (aq) + CO2(g) + H2O(l) ∆H = -1222.5 KJ/mole
Ca(s) + C(s) +2H(aq) + 3/2 O2(g) -------------> Ca^2+ (aq) + CO2(g) + H2O(l) ∆H = -1222.5 KJ/mole
CaCO3(s)+2H(aq)-- ----------------------------> Ca^2+(aq)+CO2(g)+H2O(l) ∆H= -15 KJ/mol
(-) (-) (-) (-) (-) (-) (+)
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Ca(s) + C(s) + 3/2 O2(g) --------------------> CaCO3(s) ∆H = -1207.5KJ/mole