Heat of reaction equations

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# Heat of reaction equations - PowerPoint PPT Presentation

## Heat of reaction equations

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1. Heat of reaction equations Using simultaneous equations

2. Simultaneous equations GIVEN: ΔH A + B = C -50 D + E = F +24 F + C = H ???

3. Simultaneous equations GIVEN: ΔH A + B = C -50 D + E = F +24 F + C = A+ B + C + D ???

4. Simultaneous equations GIVEN: ΔH A + B = C -50 D + E = F +24 A+ B + E + D= H -26

5. INTERPRETING DATA • In any reaction, the heat taken in or given out is determined by the direction of the reaction. • Always work left to right ΔH A + B = C - 50

6. INTERPRETING DATA • In any reaction, the heat taken in or given out is determined by the direction of the reaction. • Always work left to right ΔH A + B = C - 50 C = A + B ......

7. INTERPRETING DATA • In any reaction, the heat taken in or given out is determined by the direction of the reaction. • Always work left to right ΔH A + B = C - 50 C = A + B +50

8. INTERPRETING DATA • In any reaction, the heat taken in or given out is determined by the direction of the reaction. • Always work left to right ΔH A + B = C - 50 C = A + B +50 • If the direction of the reaction is reversed, the sign of the energy is changed (- to + or + to –)

9. Using this to solve an unknown reaction • Q6(e) The combustion of Butene C4H8 is described by the following balanced equation. C4H8 + 6O2 4CO2 + 4H2O ΔH = –2710 kJ mol–1 The standard heats of formation of water and carbon dioxide are –286 and –394 kJ mol–1, respectively. Calculate the heat of formation of C4H8

10. What have we been told?? • Q6(e) The combustion of Butene C4H8 is described by the following balanced equation. • C4H8+ 6O2 4CO2 + 4H2O ΔH = –2710 kJ mol–1 This is the energy given out when butene is burned in oxygen

11. What have we been told?? • Q6(e) The combustion of one of Butene C4H8 is described by the following balanced equation. C4H8 + 6O2 4CO2 + 4H2O ΔH = –2710 kJ mol–1 The standard heats of formation of water and carbon dioxide are –286 and –394 kJ mol–1, respectively. Calculate the heat of formation of C4H8

12. What have we been told?? The standard heats of formation of water and carbon dioxide are –286 and –394 kJ mol–1, respectively. ΔH = kJ mol–1 H2 + ½O2 H2O -286 C + O2 CO2 -394

13. What do we need to know? 4C + 4H2C4H8 ΔH = ??? Using all the given info one has to manipulate the given formulas to leave the needed one. The question seeks to answer if the formation of butene is exothermic or endothermic

14. What’s next? Write down all the info you have. ΔH = kJ mol–1 H2 + ½O2 H2O -286 C + O2 CO2 -394 C4H8 + 6O2 4CO2 + 4H2O –2710

15. What’s next? Write down all the info you have. ΔH = kJ mol–1 H2 + ½O2 H2O -286 C + O2 CO2 -394 C4H8 + 6O2 4CO2 + 4H2O –2710 4C + 4H2C4H8 ΔH = ???

16. What’s next? ΔH = kJ mol–1 H2 + ½O2 H2O -286 C + O2 CO2 -394 C4H8 + 6O2 4CO2 + 4H2O –2710 4C + 4H2C4H8 ΔH = ???

17. What’s next? ΔH = kJ mol–1 H2 + ½O2 H2O -286 C + O2 CO2 -394 C4H8 + 6O2 4CO2 + 4H2O –2710 4CO2 + 4H2O C4H8 + 6O22710 reverse 4C + 4H2C4H8 ΔH = ???

18. What’s next? ΔH = kJ mol–1 H2 + ½O2 H2O -286 C + O2 CO2 -394 C4H8 + 6O2 4CO2 + 4H2O –2710 4CO2 + 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 x4 4C + 4H2C4H8 ΔH = ???

19. What’s next? ΔH = kJ mol–1 H2 + ½O2 H2O -286 C + O2 CO2 -394 C4H8 + 6O2 4CO2 + 4H2O –2710 4CO2 + 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144 x4 4C + 4H2C4H8 ΔH = ???

20. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2 + 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144

21. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144

22. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144

23. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144

24. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144

25. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144

26. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144

27. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144 4C

28. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144 4C

29. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144 4C + 4H2

30. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144 4C + 4H2

31. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144 4C + 4H2 C4H8

32. What’s next? 4C + 4H2C4H8 ΔH = ??? ΔH = kJ mol–1 4CO2+ 4H2O C4H8 + 6O22710 4C + 4O2 4CO2 -1576 4H2 + 2O2 4H2O -1144 4C + 4H2 C4H8 -10