Q1 Zinc nitrate reacts with aqueous ammonia (NH4OH) to form a salt and a base.  
(i) Name the salt and the base.
The salt is Zinc hydroxide.The base is Ammonium nitrate.
(ii) Describe the observations for the reaction. 
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). 
ZnNO3(aq)+NH4OH(aq)-->ZnOH(s)+NH4NO3(aq)
(iv) Write an ionic equation for the reaction. 
 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. 
 (NH4)2SO4(aq)+2NaOH(aq)-->Na2SO4(aq)+2H2O(l)+2NH3(g)
(ii)  Describe a test for the gas. 
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.

The gas evolved is Ammonia gas.

(ii) This is a confirmatory test for an anion.  Name this anion.

It is Nitrate.

(iii) Give a possible cation which gives the green solution.

Iron (III) ion. 

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.

This is because Potassium Sulfate is a colourless soluble salt and there is no suitable metal, metal oxide, metal hydroxide or metal carbonate that is insoluble in water to react with it. Therefore, titration is the only way to prepare it.

(ii) Write an ionic equation for the reaction.

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. 
ZnCO3(s)+H(+)(aq)-->Zn(+)(aq)+H2O(l)+CO2(g)
(ii)  Why excess zinc carbonate is used? 
To ensure the complete reaction of the hydrochloric acid with the zinc carbonate.
(iii) Briefly explain how the zinc chloride crystals can be obtained.
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.