Chemical Thermodynamics Problem

BITSAT Papers › General Chemistry questions › Chemical Thermodynamics Problem

Determine the enthalpy change for the following reaction at 25Â°C:
C₃H₈(g) + H₂(g) â†’ C₂H₆(g) + CH₄(g)

Using the Standard Heats Of Combustion that are given below....

The Standard heat of formation of C³H₈(g) is -103.8 kJ / mol..

........................Ans: Î”H= -55.7 kJ.

Plz help !

#Chemistry #General Chemistry

UP 0 DOWN 0 0 4
Post on FacebookPost anonymously?

4 Answers

30

Ashish Kothari ·2010-09-20 01:48:35

C₃H₈ â†’ 3C + 4H₂ Î”H_f = 103.8 kJ/mol

3C + 3O₂ â†’ 3CO₂ Î”H_f = 3*(-393.5)=-1180.5kJ/mol

4H₂ + 2O₂ â†’ 4H₂O Î”H_f = 4*(-285.8)=-1143.2kJ/mol

------------------------------------------------------------------------------

C₃H₈ + 3C + 4H₂ + 5O₂ â†’ 3C + 4H₂ + 3CO₂ + 4H₂O Î”H = -2219.9 kJ/mol

H₂ + 1/2O₂ â†’ H₂O Î”H= -285.8 kJ/mol

2CO₂ + 3H₂O â†’ 7/2O₂ + C₂H₆ Î”H= 1560 kJ/mol

CO₂ + 2H₂O â†’ 2O₂ + CH₄ Î”H = 890 kJ/mol

------------------------------------------------------------------------------

C3H8(g) + H2(g) â†’ C2H6(g) + CH4(g) Î”H = -55.7 kJ/mol

UP 0 DOWN 0
Post on FacebookPost anonymously?

1

Abhisek ·2010-09-20 04:13:49

Thanks a lot for the solution ! :)

UP 0 DOWN 0
Post on FacebookPost anonymously?

30

Ashish Kothari ·2010-09-20 04:43:37

Dont say thanks yaar.. You post questions which help us too.. So feel free! :)

UP 0 DOWN 0
Post on FacebookPost anonymously?

1

Gurtej Singh ·2010-10-20 00:50:06

Simple HESS LAW.....

UP 0 DOWN 0
Post on FacebookPost anonymously?

Your Answer

Basic Integral Calculus Operators Symbols Matrix Cases

√ √ || {} [] () → ~ ^ x x x → → ln log lg lim lim cos sin tan cot arcsin arccos arctan

∫ ∫ ∫ ∫ ∫ ∬ ∬ ∬ ∬ ∬ ∭ ∭ ∭ ∭ ∭ ⨌ ⨌ ⨌ ⨌ ⨌

∑ ∑ ∑ ∑ ∑ ∮ ∮ ∮ ∮ ∮ ∏ ∏ ∏ ∏ ∏ ∐ ∐ ∐ ∐ ∐

+ - × ÷ ± ∓ = ∪ ∩ ≠ ∼ ≈ ∅ ∀ ∃ ∈ ∋ ∝ ≤ ≥ ≃ ≅ ≡ < > ≪ ≫ ⊂ ∉ ⊃ ⊆ ⊇ ⇒ ⇐ ⇔ ⇒ ⇐ ⇔ ⇑ ⇓ ⇕ → ← ↔ → ← ↔ ↑ ↓ ↕ ↖ ↗ ↘ ↙ ↪ ↩ ⇀ ↼ ⇁ ↽

° ∂ ∞ α β γ δ θ λ μ ν ξ π ρ σ φ ω ε ƒ κ τ υ Γ Δ Λ Σ Π Ω