This question is about ammonia and ammonium salts.

1. (a)(i)Ammonia is manufactured by the Haber process. Name the catalyst used in the Haber process.[1]
2. (a)(ii)Explain how a catalyst increases the rate of reaction.[1]
3. (b)Ammonium phosphate, (NH4)3PO4, is a fertiliser. Calculate the percentage by mass of nitrogen in ammonium phosphate. Give your answer to three significant figures. percentage by mass =[3]
4. (c)(i)Fertilisers can make soil more acidic. State the name of a compound used to decrease the acidity of soil.[1]
5. (c)(ii)Explain how this compound decreases the acidity of soil.[1]
6. (d)Ammonia is formed by the reduction of nitrogen(I) oxide, N2O, with hydrogen. The reaction is exothermic. N2O + 4H2 → 2NH3 + H2O Complete and label the energy profile diagram for this reaction to include: • the reactants and products • the enthalpy change of the reaction. [Figure 4.1: Energy profile diagram with axes 'energy' and 'reaction pathway', showing a curve with reactants and products, and space for enthalpy change label.][2]
7. (e)Copper(II) oxide, CuO, reacts with ammonia. The products are copper, nitrogen and a liquid which turns blue cobalt(II) chloride paper pink. Construct the equation for this reaction.[2]

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