Electrolysis Required Practical Flashcards
If the + ion (metals) were more reactive than hydrogen then hydrogen would be produced at the anode. What are the SIX possible metals the + ion could be for hydrogen to be the product for this?
- potassium
- sodium
- magnesium
- calcium
- zinc
- iron
If the + ion (metals) are less reactive then hydrogen then the metal is produced, what are the THREE possible metals the +ion could be to cause this?
- copper
- gold
- silver
If the litmus paper is bleached then what does that mean?
It means that the halogen (group 7 - ion) is produced at the anode
If there are bubbles and if there are no bubbles what does it mean? (2 points)
- Bubbles indicate hydrogen produced at CATHODE
- no bubbles indicate the metal is discharged (+ ion)
Electrolysing an ionic solution containing SULPHATE, NITRATE or CARBONATE ions produces oxygen at the anode even though there’s no oxide ions present explain why
Oxygen is produced because the hydroxide ions from the water are OXIDISED to produce OXYGEN AND WATER
Write the half equation for the oxidation of hydroxide ions during electrolysis
4OH- —-> O2 + 2H2O + 4e-
What is the half equation for the reaction at the ANODE for a HALIDE solution? (3 equations: iodine, chlorine, bromine)
- chlorine= 2CL- —-> CL2 + 2e-
- iodine= 2I- —> I2 + 2e-
- bromine= 2Br— Br2 + 2e-
What is the half equation for the reaction at the ANODE for a SULPHATE SOLUTION?
4OH- —-> O2 + 2H2O + 4E-
