0,4 mol hh X, Y và Z + NaOH thu 0,5 mol muối gly, 0,4 mol muối ala, 0,2 mol muối val

Đặt: CT Amino axit:\({C_n}{H_{2n + 1}}{O_2}N\)

\(x{C_n}{H_{2n + 1}}{O_2}Nhh\,E{C_n}{H_{2n}}{O_2}NNa\); m _{hh muối} = 120,7 gam

Ta có:

\(14n + 69 = \frac{{120,7}}{{0,4}} \Rightarrow n = \frac{{32}}{{11}};x = \frac{{1,1}}{{0,4}} = 2,75\)

\(\[2,75{C_n}{H_{2n + 1}}{O_2}N\]\overset{-1,75H_{2}O}{\rightarrow}{C_{2,75n}}{H_{5,5n - 0,75}}{O_{3,75}}{N_{2,75}}\,\left( E \right)\overset{+O_{2}}{\rightarrow}C{O_2} + {H_2}O + {N_2}\)

Đặt \({n_E} = a\left( {mol} \right)\)

\({m_{C{O_2}}} + {m_{{H_2}O}} = 44.2,75.a.n + 9\left( {5,5n - 0,75} \right)a = 78,28 \Rightarrow a = 0,16\,mol\)

\({m_{hh\,\,E}} = 0,16\left( {38,5.\frac{{32}}{{11}} - 0,75 + 16.3,75 + 14.2,75} \right) = 33,56\,\,gam\)