1. Chapter 16

2. * Method discovered by German chemist Fritz Haber in 1909. * A way to take N 2 from the air and turn it into ammonia. * Previously ammonia had been made from imported bat poo! * https://www.youtube.co m/watch?v=tdEE5uvFhOM

3. * N 2 + 3H 2  2NH 3 * Reversible reaction * Pressure = 200atm * Temp = 450 o C * Ratio of reactants: * 1N 2 : 3H 2 * N comes from the air. * H is made from natural gas. * 15% yield, unreacted reactants are recycled through. * https://www.youtube.com /watch?v=o1_D4FscMnU

4. * Between 150 – 300 atmospheres * Number of molecules on each side of the reaction: 4 and 2 * The forward reaction is favoured with high pressure. * In equilibriums involving gases, an increase in pressure favours the reaction which produces the smallest number of molecules. * We don’t use higher pressures because of the cost and danger.

5. * 400 – 500 o C * The forward reaction is exothermic, so a lower temp would favour the forward reaction. * If the temperature is increased further less ammonia will be formed. * However, at a lower temp the reaction rate would be too low. * The temp needs to be low enough to provide a good yield, but high enough to have a decent rate of reaction.

6. * Compromise conditions: the conditions which produce a reasonable yield. * Temp: 450 o C * Pressure: 200 atm

7. * The catalyst speeds up the rate of the reaction without being used up in the reaction. * It lowers the activation energy. * It does not increase the yield, only the rate. * Can be used again and again........

9. * http://www.absorblearning.com/media/item.a ction?quick=128 http://www.absorblearning.com/media/item.a ction?quick=128 * http://www.freezeray.com/flashFiles/theHabe rProcess.htm http://www.freezeray.com/flashFiles/theHabe rProcess.htm * http://www.sciencepass.com/2011/02/haber- process-including-simulation-and.html

10. * Manufacture of sulphuric acid https://www.youtube.com/watch?v=_zj3bMjFclA * Three stages * 1. Burning sulphur in air S + O 2 → SO 2 * 2. Making sulphur trioxide 2SO 2 + O 2 ⇌ 2SO 3 * 3. Making sulphuric acid H 2 SO 4 + SO 3 → H 2 S 2 O 7 H 2 S 2 O 7 + H 2 0 → 2H 2 SO 4

11. * Stage 2 = reversible reaction 2. Making sulphur trioxide 2SO 2 + O 2 ⇌ 2SO 3 -196 kj mol -1 Temperature used : 450 o C – compromise temp Pressure used : 1 – 2 atm Catalyst : Vanadium (V) oxide 99.5% conversion

12. The uses of sulphuric acid

13. * Salt is extracted from underground deposits. * The diaphragm cell is used to electrolyse the salt solution. * 3 useful chemicals can be produced: * NaOH(aq) * Cl 2 (g) * H 2 (g) * https://www.youtube.com/watch?v=JkWqNH7 OYVM

14. * Anions present: Cl - and OH - * Discharged: Cl - * Cations present: H + and Na + * H + is discharged as it is less reactive than Na + * OH - ions build up. As H + get discharged, equilibrium corrects the changes and more water molecule disassociate into OH - and H + * The diaphragm keeps the Cl - and the NaOH apart, they would react. * The solution coming out is heated and NaCl crystals are collected and reused.

15. * Soap * Paper * Aluminium * Bleach

16. * Swimming pools * Water * Bleach * Hydrochloric acid

17. * Fuel * Hydrogenation of fats, margarine