NEET (UG)

Practice Test 1 — Chemical Bonding & Molecular Structure

12 questions • 18 minutes • auto-graded with full solutions

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Section A — MCQ (Single Correct & Statement-based)

Question 1

An ionic bond is formed between:

Solution: Electron transfer from metal to non-metal.

Question 2

The shape of $\text{NH}_3$ is:

Solution: One lone pair makes it pyramidal.

Question 3

The hybridisation of carbon in $\text{C}_2\text{H}_4$ (ethene) is:

Solution: 3 sigma + 1 pi to $sp^2$.

Question 4

Statements: (I) $\text{O}_2$ is paramagnetic. (II) $\text{CO}_2$ is non-polar. Which are correct?

Solution: Both are correct.

Question 5

The bond angle in water is approximately:

Solution: Two lone pairs compress it to $104.5^{\circ}$.

Question 6

A triple bond consists of:

Solution: 1 sigma + 2 pi.

Question 7

Which molecule has an expanded octet?

Solution: Sulphur in $\text{SF}_6$ holds 12 electrons.

Question 8

The strongest intermolecular force in water is:

Solution: Hydrogen bonding dominates in water.

Section B — Assertion & Reason

Question 9

A: The bond angle in $\text{H}_2\text{O}$ is less than in $\text{NH}_3$.
R: Oxygen in water has two lone pairs, causing greater repulsion than the single lone pair in ammonia.

Solution: More lone pairs in water compress the angle further — R explains A.

Question 10

A: $\text{O}_2$ is paramagnetic.
R: Molecular orbital theory places two unpaired electrons in the antibonding $\pi^*$ orbitals of $\text{O}_2$.

Solution: The unpaired $\pi^*$ electrons are exactly why $\text{O}_2$ is paramagnetic — R explains A.

Question 11

A: $\text{CO}_2$ is a polar molecule.
R: The $\text{C}=\text{O}$ bonds in $\text{CO}_2$ are polar.

Solution: $\text{CO}_2$ is linear so the dipoles cancel — it is non-polar (A false); the bonds themselves are polar (R true).

Question 12

A: Water has an unusually high boiling point for its molar mass.
R: Water molecules are held together by intermolecular hydrogen bonds.

Solution: Hydrogen bonding raises the boiling point — R explains A.