\(n_{KOH}=\dfrac{16,8\%.300}{56}=0,9\left(mol\right)\)
PTHH: \(2KOH+CO_2\rightarrow K_2CO_3+H_2O\)
0,9---->0,45------->0,45
=> V = 0,45.22,4 = 10,08 (l)
\(m_{K_2CO_3}=0,45.138=62,1\left(g\right)\)
mdd sau pư = 0,45.44 + 300 = 319,8 (g)
=> \(C\%=\dfrac{62,1}{319,8}.100\%=19,4\%\)