How many primary () hydrogen atoms are present in a molecule of 2,2,4-trimethylpentane (isooctane)? — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

2,2,4-trimethylpentane has the structure $CH_3-C(CH_3)_2-CH_2-CH(CH_3)-CH_3$. Primary hydrogens are strictly those attached to primary carbons (methyl groups). There are 5 methyl groups: three on C2, one on C4, and C5 is a methyl. $5 \text{ groups} \times 3 \text{ H/group} = 15$ primary hydrogens.