$n_{Gly-Gly-Gly-Gly-Gly}$ = $\frac{60,6}{75.5 - 4.18}$ = 0,2mol
$n_{Gly-Gly-Gly}$ = x mol
$n_{Gly-Gly}$ = $\frac{13,2}{75.2 - 18}$ = 0,1mol
$n_{Gly}$ = $\frac{37,5}{75}$ = 0,5mol
Bảo toàn Gly:
0,2.5 = x.3 + 0,1.2 + 0,5 → x=0,1
⇒m = 0,1.(75.3 - 2.18) = 18,9 g