Redox 2

What are the features of a standard hydrogen electrode?

• I and II
• I and III
• II and III
• I, II and III

Voltaic cell is made by connecting two half-cells below. Which statement is correct?

• Mn is oxidized and voltage is 1.06 V
• Pb is oxidized and voltage is 1.06 V
• Mn is oxidized and voltage is 1.32 V
• Pb is oxidized and voltage is 1.32 V

What reaction occurs at the anode?

Ag⁺/Ag = 0.80V

Ni²⁺/Ni = -0.25V

• Ag⁺ + e^- →Ag

• Ag → Ag⁺ + e^-

• Ni²⁺ + 2e^- → Ni

• Ni → Ni²⁺ + 2e^-

As an element is oxidized, its oxidation number

• decreases as electrons are lost

• increases as electrons are lost

• decreases as electrons are gained

• increases as electrons are gained

Which represents reduction process occurring in standard hydrogen electrode?

• H_2(g) → 2H⁺_(aq) + 2e^–
• H⁺_(aq) + OH^–_(aq) → H₂O_(l)
• 2H⁺_(aq) + 2e^– → H_2(g)
• O_2(g) + 4H⁺_(aq) + 4e– → 2H₂O_(l)

Which statement is correct about value of E^ο?

• more positive value E^ο, greater driving force for reduction
• more negative value E^ο, greater driving force for reduction
• more positive value E^ο, greater the rate of reaction
• more negative value E^ο, greater the rate of reaction

What is the equation and cell potential?

• 2Al³⁺ + 3Ni → 2Al + 3Ni²⁺ E^O = 1.89 V
• 2Al + 3Ni²⁺ → 2Al³⁺ + 3Ni E^O = 1.89 V
• 2Al³⁺ + 3Ni → 2Al + 3Ni²⁺ E^O = 1.43 V
• 2Al + 3Ni²⁺ → 2Al³⁺ + 3Ni E^O = 1.43 V

What happen when zinc is added to magnesium chloride?

• No reaction will take place
• Chlorine gas will be produced
• Magnesium metal will form
• Zinc chloride will form

Which statement is correct?

• Ca²⁺ can oxidize Ni
• Ni²⁺ can reduce Ca²⁺
• Fe³⁺ can oxidize Ni
• Fe³⁺ can reduce Ca²⁺

The salt bridge is best prepared by soaking filter paper in

• 1 mol dm^-3 solution of potassium bromide

• 1 mol dm^-3 solution of potassium chloride

• saturated solution of potassium nitrate

• saturated solution of potassium iodide