7 Methane gas is used as a fuel source for mechanical devices Hydrogen gas

# 7 methane gas is used as a fuel source for mechanical

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7) Methane gas is used as a fuel source for mechanical devices. Hydrogen gas reacts with graphite to produce this fuel source. Use the following thermochemical equations to determine the o rxn ΔH the reaction to produce methane gas. C (s, graphite) + O 2(g) CO 2(g) Δ H o = -393.5 kJ/mol CH 4(g) + 2O 2(g) CO 2(g) + 2H 2 O (l) Δ H o = -890.3 kJ/mol
CHEM111 Week 6 Discussion Questions Fall 2014 H 2(g) + 1 2 O 2(g) H 2 O (l) Δ H o = -285.8 kJ/mol C (s, graphite) + O 2(g) CO 2(g) Δ H o = -393.5 kJ/mol CO 2(g) + 2H 2 O (l) CH 4(g) + 2O 2(g) -1* Δ H o = 890.3 kJ/mol 2H 2(g) + O 2(g) 2H 2 O (l) 2* Δ H o = -571.6 kJ/mol _________________________________________________ C (s, graphite) + 2 H 2(g) CH 4(g) o rxn ΔH = -74.8 kJ/mol of reaction 8) Determine the oΔHrxnfor C(diamond) C(graphite) based on enthalpy change of the following reactions: (1) C(diamond) + O 2 (g) CO 2 (g) H 395.4 kJ/mol Δ = (2) 2CO 2 (g) 2CO(g) + O 2 (g) H 566.0 kJ/mol Δ = (3) C (graphite) + O 2 (g) CO 2 (g) H 393.5 kJ/mol Δ = (4) 2CO(g) C(graphite) + CO 2 (g) H 172.5 kJ/mol Δ = 9) One cubic meter (1 m 3 ) of natural gas produces an average of 35,301BTU when burned. Natural gas is CH 4 . Determine the conversion between BTU and kJ using the following information. CH 4 density = 0.656 g/L Compound Δ H f º (kJ/mol) CH 4 (g) –74.8 CO 2 (g) –393.5
CHEM111 Week 6 Discussion Questions Fall 2014 H 2 O(g) –241.8 10) Use bond enthalpy values to calculate the enthalpy of reaction. CH 4 + 2O 2 → CO 2 + 2H 2 O C-C 346 kJ/mol C-H 411 kJ/mol H-H 432 kJ/mol C=C 602 kJ/mol O-O 204 kJ/mol O-H 464 kJ/mol C=O 804 kJ/mol O=O 494 kJ/mol N-N 160 kJ/mol Δ H o =4(C-H)+3/2(O=O)-2(C=O)-4(O-H) =4(411 kJ/mol) + 2(494 kJ/mol) – 2(804 kJ/mol) – 4(464 kJ/mol) =-832 kJ/mol C H H H H O O O C O O H H

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