R3.2 Electron transfer reactions (SL)
15 revision questions with answers for R3.2 Electron transfer reactions (SL). Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
Loss of electrons by a species?
- Reduction
- Neutralisation
- Hydration
- OxidationRight answer
What this set covers
Redox at SL: oxidation and reduction, oxidation states, half-equations, oxidising and reducing agents, voltaic cells and salt bridges, secondary cells, electrolysis of molten NaCl, and oxidising alcohols with acidified dichromate(VI).
- Common mix-up
- Students often mix up anode and cathode: oxidation always occurs at the anode, and in a voltaic cell electrons flow from anode to cathode through the external circuit.
- Revision tip
- Draw a Zn/Cu voltaic cell, label anode, cathode, salt bridge and electron flow, then write both half-equations.
All 15 questions and answers
Loss of electrons by a species?
Answer: Oxidation
Oxidation state of manganese in KMnO₄?
Answer: +7
Oxidation state of sulfur in SO₄²⁻?
Answer: +6
Species that accepts electrons and so is itself reduced?
Answer: Oxidising agent
Electrons transferred per zinc atom in Zn + Cu²⁺ → Zn²⁺ + Cu?
Answer: 2
Half-equation for the oxidation of iron(II) ions?
Answer: Fe²⁺ → Fe³⁺ + e⁻
Gas formed when magnesium reacts with dilute hydrochloric acid?
Answer: Hydrogen
Electrode at which oxidation occurs?
Answer: Anode
In a primary (voltaic) cell, electrons flow through the external circuit from…?
Answer: Anode to cathode
Component that lets ions move between the two half-cells?
Answer: Salt bridge
Rechargeable cell, such as a lithium-ion battery?
Answer: Secondary cell
Product at the cathode in the electrolysis of molten NaCl?
Answer: Sodium
Product of heating ethanol under reflux with excess acidified K₂Cr₂O₇?
Answer: Ethanoic acid
Product of oxidising propan-2-ol with acidified K₂Cr₂O₇?
Answer: Propanone
Colour change of acidified dichromate(VI) as it oxidises an alcohol?
Answer: Orange to green
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.