Question 12

Nylon 6,6 is synthesized from hexamethylenediamine ($H_2N-(CH_2)_6-NH_2$) and adipic acid. Hexamethylenediamine is a primary amine and thus gives a positive carbylamine test. Therefore, $X$ is hexamethylenediamine ($C_6H_{16}N_2$). In Dumas method, all nitrogen in the compound is converted to $N_2$ gas. 1 mole of $X$ contains 2 moles of N atoms, which produce 1 mole of $N_2$ gas. 10 moles of $X$ will produce 10 moles of $N_2$ gas. Mass of $N_2$ gas = $10\ mol \times 28\ g\ mol^{-1} = 280\ g$.