A completely dry, pure sample of an unknown organic compound possessing active hydrogen atoms is tes — Hydrocarbons Chemistry Question
Question
A completely dry, pure sample of an unknown organic compound possessing active hydrogen atoms is tested using Zerewitnoff's active hydrogen determination method. If 1 mole of this compound completely reacts with an excess of methylmagnesium iodide ($CH_3MgI$) to liberate exactly 3 moles of methane gas, how many active hydrogen atoms are present in one molecule of the unknown compound?
💡 Solution & Explanation
Grignard reagents ($RMgX$) react quantitatively with compounds containing active hydrogens (like $-OH, -NH_2, -COOH, -C\equiv CH$) to produce an alkane corresponding to the Grignard's alkyl group. One mole of active hydrogen reacts with one mole of Grignard reagent to produce one mole of the alkane. Since 3 moles of methane are liberated per mole of the compound, the compound must contain 3 active hydrogen atoms.