1)
Ta có:
\({m_{NaOH}} = 60.5\% = 3{\text{ gam}}\)
\({m_{dd}} = 40 + 60 = 100{\text{ gam}}\)
\( \to C{\% _{NaOH}} = \frac{3}{{100}} = 3\% \)
2)
100 gam dung dịch \(KOH\) 20% chứa
\({m_{KOH}} = 100.20\% = 20{\text{ gam}}\)
50 gam dung dịch \(KOH\) 15% chứa:
\({m_{KOH}} = 50.15\% = 7,5{\text{ gam}}\)
\( \to {m_{KOH}} = 20 + 7,5 = 27,5{\text{ gam}}\)
\({m_{dd}} = 100 + 50 = 150{\text{ gam}}\)
\( \to C{\% _{KOH}} = \frac{{27,5}}{{150}} = 18,333\% \)