Ammonia, NH3, is used to make nitrogenous fertilisers.

1. (a)Ammonia is manufactured using the reversible reaction between nitrogen and hydrogen. Construct the equation for this reversible reaction.[2]
2. (b)(i)Ammonia is used to make the soluble salt ammonium nitrate, NH4NO3. Name the acid that reacts with ammonia to make ammonium nitrate.[1]
3. (b)(ii)Calculate the percentage by mass of nitrogen in ammonium nitrate. percentage by mass[2]
4. (c)(i)Nitrogenous fertilisers such as ammonium nitrate leach from farmland and cause water pollution problems in rivers and lakes. Name the process caused by this type of water pollution.[1]
5. (c)(ii)Explain why this type of water pollution problem is increased when nitrate fertilisers are used instead of other fertilisers.[1]
6. (d)(i)A farmer adds ammonium nitrate, NH4NO3, to soil. The farmer then adds calcium hydroxide, Ca(OH)2, to the same soil. State the purpose of adding calcium hydroxide to soil.[1]
7. (d)(ii)Construct the equation for the reaction between ammonium nitrate and calcium hydroxide. Using your equation, explain why the ammonium nitrate fertiliser is less effective after calcium hydroxide is added.[2]