HSC Chemistry — Module 8
Electrochemical Series — Flashcards & Quiz
The electrochemical series ranks metals and half-reactions by their standard reduction potentials. In HSC Chemistry, you use this table to predict which redox reactions are spontaneous, determine the anode and cathode in galvanic cells, and calculate cell voltages. Being able to quickly read the table and apply it to unfamiliar reactions is essential. Exam questions commonly ask you to predict products of electrolysis, compare galvanic and electrolytic cells, or explain why certain metals corrode faster than others.
Sample Flashcards
Q1: What is the electrochemical series?
A ranking of elements and their half-reactions in order of standard reduction potential (E\u00B0). More positive E\u00B0 values indicate a stronger tendency to be reduced (gain electrons).
Q2: How do you predict whether a redox reaction is spontaneous?
A redox reaction is spontaneous if the overall cell potential (E\u00B0cell) is positive. E\u00B0cell = E\u00B0cathode \u2212 E\u00B0anode.
Q3: In a galvanic cell, which electrode is the anode and which is the cathode?
The anode is where oxidation occurs (more negative E\u00B0). The cathode is where reduction occurs (more positive E\u00B0). Electrons flow from anode to cathode through the external circuit.
Q4: What is the role of the salt bridge in a galvanic cell?
The salt bridge maintains electrical neutrality by allowing ions to flow between the two half-cells. Without it, charge buildup would stop the reaction.
Q5: How do you calculate the EMF of a galvanic cell?
EMF = E\u00B0cathode \u2212 E\u00B0anode. Use the standard reduction potentials from the electrochemical series. The half-cell with the more positive E\u00B0 is the cathode.
Sample Quiz Questions
Q1: Zinc (E\u00B0 = \u22120.76 V) and copper (E\u00B0 = +0.34 V) are used in a galvanic cell. What is the cell voltage?
Answer: 1.10 V
E\u00B0cell = E\u00B0cathode \u2212 E\u00B0anode = (+0.34) \u2212 (\u22120.76) = 1.10 V. Copper is the cathode and zinc is the anode.
Q2: Metals with more negative standard reduction potentials are:
Answer: Stronger reducing agents
Metals with more negative E\u00B0 values have a greater tendency to lose electrons (be oxidised), making them stronger reducing agents.
Q3: Why do galvanic cells eventually stop producing electricity?
Answer: The reactants are consumed and the system reaches equilibrium
As reactants are used up, the concentration gradient that drives the reaction diminishes until the cell potential drops to zero at equilibrium.
Last updated: March 2026 · 5 flashcards · 3 quiz questions