The zinc sulfide in the ore is changed into zinc oxide first. Describe how zinc oxide is produced from zinc sulfide.
Write a chemical equation for the reaction in (a)(i).
Explain how zinc oxide is converted into zinc. Your response should make clear how the heat is generated and should include equations for every reaction you mention.
Explain why the zinc formed inside the furnace is a gas.
State the name of the physical change when gaseous zinc becomes molten zinc.
Rusting of steel can be stopped by covering the steel with a zinc layer. Explain, in terms of electron transfer, why the steel does not rust even if the zinc layer is scratched so that air and water can reach the steel.
Add aqueous sodium hydroxide to the iron(II) chloride and iron(III) chloride solutions. Fill in the table below to show the observations you would expect.
What sort of substance makes potassium iodide solution change from colourless to brown?
What sort of substance makes acidified potassium manganate(VII) solution change from purple to colourless?
Which ion in iron(III) chloride solution causes potassium iodide solution to change from colourless to brown?
Which ion in iron(II) chloride solution causes acidified potassium manganate(VII) solution to change from purple to colourless?