ECAT Chemistry — Basic Concepts
Basic Concepts is part of the Chemistry section of the UET ECAT (30 of the 100 MCQs). It breaks into 3 subtopics, and we hold 34 ECAT-pattern practice MCQs on it, each with a written explanation. Tap a subtopic below to practise just that.
Subtopics (3)
How Basic Concepts is tested
Across the 7 ECAT past papers on ParhaiKrlo, Basic Concepts accounts for 8 questions. It appears in 5 of them, about 1.6 questions a paper. The heaviest was ECAT Past Paper 04, with 3 questions, and the most recent is ECAT Past Paper 07, with 2.
| Paper | Questions |
|---|---|
| ECAT Past Paper 07 | 2 |
| ECAT Past Paper 06 | 1 |
| ECAT Past Paper 05 | 1 |
| ECAT Past Paper 04 | 3 |
| ECAT Past Paper 03 | 1 |
Basic Concepts MCQs from the ECAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · ECAT Past Paper 07 · Basic Concepts
The empirical formula of glucose is:
- A.CH₂O
- B.CH
- C.C₆H₁₂O₆
- D.CHO
Show answer
Answer: A. CH₂O — C₆H₁₂O₆ reduces by 6 to CH₂O.
- Q2 · ECAT Past Paper 06 · Basic Concepts
Which ion has more electrons than protons and more protons than neutrons? (D = ²₁H, He = ⁴₂He, O = ¹⁶₈O, H = ¹₁H)
- A.D⁻
- B.D₃O⁺
- C.He⁺
- D.OH⁻
Show answer
Answer: D. OH⁻ — OH⁻: 9 protons, 8 neutrons, 10 electrons.
- Q3 · ECAT Past Paper 05 · Basic Concepts
How many carbon atoms are there in 18 g of C₆H₁₂O₆?
- A.6.02 × 10²³
- B.3.6 × 10²³
- C.6.02 × 10²²
- D.3.6 × 10²²
Show answer
Answer: B. 3.6 × 10²³ — 18/180 = 0.1 mol glucose → 0.6 mol C → 0.6 × 6.02 × 10²³ ≈ 3.6 × 10²³ atoms.