Q1 Zinc nitrate reacts with aqueous ammonia (NH4OH) to form a salt and a base. 
(i) Name the salt and the base.
Ans:The salt is Zinc hydroxide.The base is Ammonium nitrate.
(ii) Describe the observations for the reaction.
Ans:A white precipitate is formed when the two aqueous solutions(Zinc nitrate and aqueous ammonia)are introduced to each other.
(iii) Write a chemical equation for the reaction (include state symbols).
Ans:ZnNO3(aq)+NH4OH(aq)-->ZnOH(s)+NH4NO3(aq)
(iv) Write an ionic equation for the reaction. 
Ans: Zn(+)(aq)+OH(-)(aq)-->ZnOH(s)

Q2 Ammonium sulfate is heated with sodium hydroxide.
(i) Write a chemical equation (include state symbols) for the reaction. 
Ans: (NH4)2SO4(aq)+2NaOH(aq)-->Na2SO4(aq)+2H2O(l)+2NH3(g)
(ii)  Describe a test for the gas.
Ans:Hold a piece of damp red litmus paper above the solutions reacting.


Q3 An unknown green solution is heated with a piece of aluminium foil and sodium hydroxide solution. 
(i) The gas produced turns damp red litmus paper blue.  Name the gas evolved.
Ans:Ammonia
(ii) This is a confirmatory test for an anion.  Name this anion. 
Ans:Nitrate
(iii) Give a possible cation which gives the green solution.
Ans:Iron(III)


Q4 Sulfuric acid is titrated with potassium hydroxide in the preparation of potassium sulfate salt. 
(i) Explain why this method is recommended for the preparation for this salt. 
Ans:The salt produced is soluble and in Group(I),which is the type of salt that is produced through titration.
(ii) Write an ionic equation for the reaction.
Ans:H(+)(aq)+OH(-)(aq)-->H2O(l)

Q5 Excess zinc carbonate is added to hydrochloric acid in the preparation of zinc chloride salt.
(i) Write an ionic equation for the reaction.
Ans:ZnCO3(s)+H(+)(aq)-->Zn(+)(aq)+H2O(l)+CO2(g)
(ii)  Why excess zinc carbonate is used?
Ans:To ensure the complete reaction of the hydrochloric acid with the zinc carbonate.
(iii) Briefly explain how the zinc chloride crystals can be obtained.
Ans:After the reaction of the zinc carbonate with the hydrochloric acid,filter and heat the filtrate until there is a small amount of water for crystalization.