\(HCOOH+NaOH\rightarrow HCOONa+H_2O\)
\(CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O\)
\(n_{HCOOH}=a\left(mol\right),n_{CH_3COOH}=b\left(mol\right)\)
\(m_X=46a+60b=10.6\left(g\right)\left(1\right)\)
\(n_{NaOH}=a+b=0.2\left(mol\right)\left(2\right)\)
\(\Rightarrow a=b=0.1\)
\(m_{HCOOH}=0.1\cdot46=4.6\left(g\right)\)
\(m_{CH_3COOH}=6\left(g\right)\)
\(n_{H_2O}=0.2\left(mol\right)\)
\(BTKL:\)
\(m_{Muối}=10.6+0.2\cdot40-0.2\cdot18=15\left(g\right)\)