Đáp án:
\(\begin{array}{l}
9.CM = \dfrac{{10 \times D \times C\% }}{M}\\
10.C{M_{NaCl}} = 3,75M
\end{array}\)
Giải thích các bước giải:
9.
Ta có: Lấy V lít hay 1000V ml dung dịch
\(\begin{array}{l}
D = \dfrac{m}{V} \to {m_{{\rm{dd}}}} = 100V.D\\
\to {m_{c\tan }} = \dfrac{{{m_{{\rm{dd}}}}}}{{100\% }} \times C\% = \dfrac{{1000V \times D}}{{100\% }} \times C\% = 10V \times D \times C\% \\
\to {n_{c\tan }} = \dfrac{{mc\tan }}{M} = \dfrac{{10V \times D \times C\% }}{M}\\
CM = \dfrac{{{n_{c\tan }}}}{V} = \dfrac{{\dfrac{{10V \times D \times C\% }}{M}}}{V}\\
\to CM = \dfrac{{10 \times D \times C\% }}{M}
\end{array}\)
\(\begin{array}{l}
10.\\
{m_{NaCl}} = \dfrac{{200 \times 15\% }}{{100\% }} = 30g\\
\to {n_{NaCl}} = 0,75mol\\
\to {V_{NaCl}} = \dfrac{{200}}{{1,1}} = 181,82ml = 0,2l\\
\to C{M_{NaCl}} = \dfrac{{0,75}}{{0,2}} = 3,75M
\end{array}\)
