Quiz | Electrochemistry
General Chemistry 3 - Quiz
Which of the following statements is incorrect?
It is not possible to directly measure the voltage of a single electrode but it can be determined by measuring the voltage difference between a standard electrode and the desired electrode ⇒ in electrochemistry, a Standard Hydrogen Electrode (SHE) is used
Which of the following statement about salt bridge is correct?
Salt bridge provides an ionic current path between the 2 solutions with electrodes in order to maintain the charge balance in the cell
Why is Standard Hydrogen Electrode (SHE) called as the primary reference electrode?
By convention, the voltage of the SHE is E0 = 0 V ⇒ SHE is the primary reference electrode
2 H+ (aq) + 2 e- → H2 (g) [E0red = 0 V]
What is the reaction of the zinc-copper cell: Zn (s) | ZnSO4(aq) || CuSO4(aq) | Cu(s)?
By convention:
- left-hand electrode: oxidation reaction ⇒ Zn (s) → Zn2+ (aq) + 2 e-
- right-hand electrode: reduction reaction ⇒ Cu2+ (aq) + 2 e- → Cu (s)
What is the half-reaction that occurs at the anode during the electrolysis of sodium bromide?
Electrolysis of NaBr: 2 Br- (aq) + 2 Na+ (aq) → Br2 (l) + 2 Na (s)
Anode: oxidation reaction ⇒ 2 Br- → Br2 + 2 e-
What is the correct Nernst equation for the reaction: Cu (s) + Zn2+ (aq) → Zn (s) + Cu2+ (aq)?
Nernst equation: E = E0 – ln Q
Cu (s) + Zn2+ (aq) → Zn (s) + Cu2+ (aq) can be broken down into 2 half reaction equations:
Cu (s) → 2 e- + Cu2+ (aq) and Zn2+ (aq) + 2 e- → Zn (s)
⇒ stoichiometric coefficient of the electrons in the 2 half reaction equations νe = 2