## 3 Cu (s) + 8 HNO3 (aq) → 3 Cu(NO3)2 (aq) + 2 NO (g) + 4 H2O (ℓ)

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## Stoichiometry

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 Cu             Mass: g HNO3           Mass: g or Solution Volume: mL of Concentration: mol/L Cu(NO3)2       Mass: g NO             Mass: g or Gas Volume: L H2O            Mass: g Heat Released: kJ

## Enthalpy of Reaction

[3ΔHf(Cu(NO3)2 (aq)) + 2ΔHf(NO (g)) + 4ΔHf(H2O (ℓ))] - [3ΔHf(Cu (s)) + 8ΔHf(HNO3 (aq))]
[3(-349.95) + 2(90.25) + 4(-285.83)] - [3(0) + 8(-207.36)] = -353.79 kJ
-353.79 kJ     (exothermic)

## Entropy Change

[3ΔSf(Cu(NO3)2 (aq)) + 2ΔSf(NO (g)) + 4ΔSf(H2O (ℓ))] - [3ΔSf(Cu (s)) + 8ΔSf(HNO3 (aq))]
[3(193.3) + 2(210.65) + 4(69.91)] - [3(33.15) + 8(146.44)] = 9.87000000000012 J/K
9.87 J/K     (increase in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[3ΔGf(Cu(NO3)2 (aq)) + 2ΔGf(NO (g)) + 4ΔGf(H2O (ℓ))] - [3ΔGf(Cu (s)) + 8ΔGf(HNO3 (aq))]
[3(-157.16) + 2(86.57) + 4(-237.18)] - [3(0) + 8(-111.34)] = -356.34 kJ
-356.34 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-356.73 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

2.7011006116e+062
This process is favorable at 25°C.

## Reference(s):

Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 135.