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Câu hỏi: Cho 6,57 gam
A. 14,97
B. 14,16
C. 13,35
D. 11,76
A. 14,97
B. 14,16
C. 13,35
D. 11,76
Cách 1:
$\begin{aligned}
& {{n}_{Ala-Gly}}=\dfrac{6,57}{89+75-18}=0,045\ mol \
& {{n}_{KOH}}=0,15\ mol \
& Ala-Gly+2KOH\to AlaK+GlyK+{{H}_{2}}O \
& \ \ \ \ \ \ \ 0,045\to 0,09\ \ \ \ \ 0,045\ \ \ \ 0,045\ \ 0,045 \
& \to m\ gam\ \left\{ \begin{aligned}
& AlaK:0,045 \
& GlyK:0,045 \
& KOH\left( du \right):0,06 \
\end{aligned} \right.\to m=127.0,045+113.0,045+56.0,06=14,16\ gam \
\end{aligned}$
Cách 2:
$\begin{aligned}
& {{n}_{Ala-Gly}}=\dfrac{6,57}{89+75-18}=0,045\ mol \
& {{n}_{KOH}}=0,15\ mol \
& Ala-Gly+2KOH\to AlaK+GlyK+{{H}_{2}}O \
& \ \ \ \ \ \ \ 0,045\to 0,09\ \ \ \ \ 0,045\ \ \ \ 0,045\ \ 0,045 \
& \to m\ gam\ \left\{ \begin{aligned}
& AlaK:0,045 \
& GlyK:0,045 \
& KOH\left( du \right):0,06 \
\end{aligned} \right.\to m=127.0,045+113.0,045+56.0,06=14,16\ gam \
\end{aligned}$
Cách 2:
Đáp án B.