Question

an unknown amine is treated with excess of methyl iodide. 2 equivalents of methyl iodide react with amine. The amine is treated with silver oxide and water and then heated to 120° C. The resulting products are trimethylamine and ethylene. The unkown amine is

Answer 1

The unknown amine should be secondary amine because when we add 2 equivalents of $C H_{3} I$ the thing which will be formed is known as quaternary ammonium iodide which will give tertiary amine which is water and alkene after it is treated with silver hydroxide and is heated. This is what usually happens when one of the alkyl group is other than methyl.