ECAT Chemistry — Electrochemistry
Electrochemistry is part of the Chemistry section of the UET ECAT (30 of the 100 MCQs). It breaks into 3 subtopics, and we hold 43 ECAT-pattern practice MCQs on it, each with a written explanation. Tap a subtopic below to practise just that.
Subtopics (3)
How Electrochemistry is tested
Across the 7 ECAT past papers on ParhaiKrlo, Electrochemistry accounts for 20 questions. It appears in 6 of them, about 3.3 questions a paper. The heaviest was ECAT Past Paper 06, with 5 questions, and the most recent is ECAT Past Paper 07, with 4.
| Paper | Questions |
|---|---|
| ECAT Past Paper 07 | 4 |
| ECAT Past Paper 06 | 5 |
| ECAT Past Paper 05 | 4 |
| ECAT Past Paper 04 | 5 |
| ECAT Past Paper 03 | 1 |
| ECAT Past Paper 02 | 1 |
Electrochemistry MCQs from the ECAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · ECAT Past Paper 07 · Electrochemistry
The oxidation number of sulphur in SO₄²⁻ is:
- A.+6
- B.+4
- C.−6
- D.+2
Show answer
Answer: A. +6 — x + 4(−2) = −2 gives x = +6.
- Q2 · ECAT Past Paper 06 · Electrochemistry
In an alkaline battery, the anode, the cathode and the electrolyte are, respectively:
- A.Manganese dioxide, zinc, sodium hydroxide
- B.Zinc, manganese dioxide, sodium hydroxide
- C.Zinc, manganese dioxide, potassium hydroxide
- D.Manganese dioxide, zinc, potassium hydroxide
Show answer
Answer: C. Zinc, manganese dioxide, potassium hydroxide — Zn anode (oxidised), MnO₂ cathode (reduced), KOH electrolyte.
- Q3 · ECAT Past Paper 05 · Electrochemistry
In which reaction does hydrogen behave as an oxidizing agent?
- A.H₂ + Cl₂ → 2HCl
- B.CH₃CHO + H₂ → CH₃CH₂OH
- C.2Na + H₂ → 2NaH
- D.C₂H₄ + H₂ → C₂H₆
Show answer
Answer: C. 2Na + H₂ → 2NaH — With sodium, hydrogen gains electrons (forms H⁻), so it is reduced and acts as the oxidizing agent.