The concept of electrolysis
Answers are for parents and teachers.
1
How many moles of electrons pass through the anode when 5 mol of Cl₂ form from molten CaCl₂?
10
2
Write the equation of the electrolysis of aqueous AgNO₃ and name the products at the electrodes.
4AgNO₃ + 2H₂O → 4Ag + O₂ + 4HNO₃; Ag at the cathode, O₂ at the anode.
3
Write the equation of the electrolysis of aqueous NaBr.
2NaBr + 2H₂O → H₂ + Br₂ + 2NaOH
4
How many moles of electrons are needed to form 3 mol of Al in the electrolysis of molten Al₂O₃? (Al³⁺ + 3e⁻ → Al)
9
5
Why is aluminium obtained from a melt rather than an aqueous solution?
In aqueous solution H₂, not Al, forms at the cathode.