Preferential Discharge-Concentration of Electrolyte

Multiple Choice

Identify the ions present in concentrated zinc chloride, ZnCl₂ solution.

i. Zn²⁺

ii. H⁺

iii. OH^-

iv. Cl^-

v. Cl₂

• i and iv only.

• i and v only

• i, ii, iii and v only.

• i, ii, iii and iv only.

Multiple Choice

Identify the ions in concentrated Lithium chloride solution which would migrate to the anode (+ve electrode).

• Li⁺_(aq) and Cl^-_(aq)

• OH^-_(aq) only.

• OH^-_(aq) and Cl^-_(aq)

• Cl^-_(aq) only.

Multiple Choice

For the electrolysis of dilute potassium chloride solution, what observation would you expect to make at the anode?

• Effervescence, colourless, odourless gas produced which relights a glowing splint.

• Effervescence, yellow-green, pungent gas produced.

• Effervescence, colourless, odourless gas produced which outs a burning splint with a pop.

• Silver solid deposited.

Multiple Choice

For the electrolysis of concentrated potassium chloride solution, what observation would you expect to make at the anode?

• Effervescence, colourless, odourless gas produced which relights a glowing splint.

• Effervescence, yellow-green, pungent gas produced.

• Effervescence, colourless, odourless gas produced which outs a burning splint with a pop.

• Silver solid deposited.

Multiple Choice

Which of the following electrolytes would give the following observation at the anode?

Red brown solution formed.

• Dilute Potassium bromide solution.

• Dilute sodium bromide.

• Concentrated aqueous Lithium bromide.

• Concentrated copper sulphate solution.

Multiple Choice

Identify the ions in concentrated Lithium chloride solution which would migrate to the cathode (-ve electrode).

• Li⁺_(aq) and H⁺_(aq)

• Li⁺_(aq) only.

• Li⁺_(aq) and Cl^-_(aq)

• H⁺ only.

Multiple Choice

For the electrolysis of concentrated potassium chloride solution, what observation would you expect to make at the cathode?

• Effervescence, colourless, odourless gas produced which relights a glowing splint.

• Effervescence, yellow-green, pungent gas produced.

• Effervescence, colourless, odourless gas produced which outs a burning splint with a pop.

• Silver solid deposited.

Multiple Choice

For the electrolysis of concentrated copper chloride solution, what observation would you expect to make at the cathode?

• Effervescence, colourless, odourless gas produced which relights a glowing splint.

• Effervescence, yellow-green, pungent gas produced.

• Effervescence, colourless, odourless gas produced which outs a burning splint with a pop.

• Salmon/brown solid deposited.

Multiple Choice

What changes would you expect to occur in the electrolyte after electrolysis of concentrated sodium bromide solution.

• Turns red litmus blue.

• Turns blue litmus red.

• No change.

• It becomes more concentrated.

Multiple Choice

Electrolysis of dilute sodium chloride solution results in the electrolyte becoming more concentrated. Suggest an explanation for this.

• The concentration of H⁺ becomes less than OH^-.

• The concentration of OH^- becomes less than H⁺.

• H⁺ and OH^- (ions from water) are both discharged at respective electrodes.

• Na⁺ and Cl^- are discharged at their respective electrodes.