Question

Concentrated aqueous potassium chloride is electrolyzed using platinum electrodes. The solution contains the ions K, Cl, H⁺, and OH⁻. Which electrodes are the ions attracted to during this electrolysis?

a) Anode: Cl⁻ and OH⁻; Cathode: H⁺ and K⁺
b) Anode: H⁺ and OH⁻; Cathode: Cl⁻ and K⁺
c) Anode: Cl⁻ and K⁺; Cathode: H⁺ and OH⁻
d) Anode: H⁺ and K⁺; Cathode: Cl⁻ and OH⁻

Answer 1

During the electrolysis of concentrated aqueous potassium chloride with platinum electrodes, cations (H+ and K+) move to the cathode, and anions (Cl- and OH-) move to the anode. The correct answer is a) Anode: Cl- and OH-; Cathode: H+ and K+.

Step-by-step explanation:

When concentrated aqueous potassium chloride is electrolyzed using platinum electrodes, certain ions move towards the anode and others towards the cathode. Ions with a positive charge, known as cations (K+ and H+), are attracted to the cathode, which is the negative electrode. Conversely, ions with a negative charge, known as anions (Cl− and OH−), are attracted to the anode, which is the positive electrode. Considering the relative ease of discharge and the standard electrode potentials, H+ ions are reduced at the cathode preferentially over K+, and Cl− ions are oxidized at the anode in preference to OH−. Therefore, the correct answer is a) Anode: Cl− and OH−; Cathode: H+ and K+.