Question

1. which of the following diagrams is the correct lewis dot structure for a molecule of ethyne, c₂h₂?

oa h - c = c -
ob h = c = c =
oc h - c ≡ c -
od h - c - c -

Explanation:

Ethyne (\(C_2H_2\)) has a triple bond between the two carbon atoms. Each carbon atom forms a single bond with a hydrogen atom. In Lewis dot structures, single bonds are represented by a single line (\(-\)), double bonds by \(=\), and triple bonds by \(\equiv\). Option A has incorrect electron distribution around carbon (carbon should have 4 valence - electron - related bonds or lone pairs accounted for, here the dot - structure around carbon is wrong). Option B has an incorrect bond type (hydrogen can only form one single bond, not a double bond). Option D has only single bonds between carbons and incorrect electron distribution (carbons should have a triple bond between them). Option C correctly shows the single \(C - H\) bonds and the \(C\equiv C\) triple bond.

Answer:

C. \(H - C\equiv C - H\)