IGCSE Organic Chemistry Practice Test 2026 - Free Organic Chemistry Practice Questions and Study Guide

Hydrogenation adds hydrogen across a carbon–carbon double bond, converting the C=C into a single bond and giving a saturated hydrocarbon. So an alkene reacts with H2 under metal catalyst to form an alkane. The other options would require introducing oxygen (a diol), forming a triple bond (an alkyne) or oxidizing to a carboxylic acid, none of which come from simple hydrogenation of an alkene. Therefore, the product is an alkane.