Chemistry Chemical Bonding MDCAT 2016
PMDC Verified Question 93 of 102
Count the number of \( \sigma \) (sigma) bonds and \( \pi \) (pi) bonds in the molecule of Ethene \( \left( \text{H}_2\text{C}=\text{CH}_2 \right) \):
A
1 \( \pi \) and 5 \( \sigma \) bonds
B
3 \( \pi \) and 3 \( \sigma \) bonds
C
2 \( \pi \) and 4 \( \sigma \) bonds
D
6 \( \pi \) and 6 \( \sigma \) bonds
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: 1 \( \pi \) and 5 \( \sigma \) bonds
Concept:

Every single bond is a sigma (\( \sigma \)) bond, and every double bond consists of one \( \sigma \) bond and one pi (\( \pi \)) bond.

Formula:

$$ \text{Total Bonds} = 4 \times (\text{C-H}) + 1 \times (\text{C=C}) $$

Solution:

  • There are 4 Carbon-Hydrogen single bonds, contributing 4 \( \sigma \) bonds.


  • There is 1 Carbon-Carbon double bond. This contributes 1 \( \sigma \) bond and 1 \( \pi \) bond.


  • Total \( \sigma \) bonds = \( 4 + 1 = 5 \).


  • Total \( \pi \) bonds = 1.


Why other options are incorrect:

  • Option B, Option C, Option D: These incorrectly count the fundamental bond types, likely confusing the number of electrons (a double bond has 4 electrons) with the number of discrete bonds.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Chemical Bonding MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App