CH3.2 Redox reaction

Question 1

what do you use to balance charges on half equations

Answer 1

Electrons and protons (e- H+)

Question 2

what must you cancel when combining half equations

Answer 2

times one/both of the half equations so that once the combine the electrons will cancel.

Question 3

redox titration exsplained

Answer 3

• 25cm3 of solution measured into a volumetric pipetter and placed into a conical flask. add indicator
• secound solution is added a little at a tie from a burette
• make sure the chonical flask is being continuesly mixed as the secoudn solutiong is being added
• continue adding solution unitil there is a colour chagne.
• titre taken from the burette
• calculation looking at moles, mass, concentration, mr and volume of the solutions.

Question 4

redox titration of copper(II) ions

Answer 4

• can not be done directly
• colourless soolution contatining iodide ions such as potassium iodide is added to ablue solution contatining copper (II) ions.
• formation of brown solution
• copper(II) ions in solution react with the iodide ions to genertae a brown solution.
• reduced to copper(I) in a precipitate of Cul
• titrates with sodium thiosulfate to work out the original amount of copper(II)

I2 + 2e- –> 2I- (brown to colourless)