Đáp án:
\(\begin{array}{l}
a,{m_{{\rm{dd}}}} = 50g\\
b,{m_{{H_2}O}} = 45g
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
a,{m_{{\rm{dd}}}} = \dfrac{{{m_{NaOH}}}}{{C\% }} \times 100\% = \dfrac{5}{{10\% }} \times 100\% = 50g\\
b,\\
{m_{NaOH}} + {m_{{H_2}O}} = {m_{{\rm{dd}}}}\\
\to {m_{{H_2}O}} = {m_{{\rm{dd}}}} - {m_{NaOH}} = 45g
\end{array}\)