Phản ứng xảy ra:
\(MnO_2+4HCl\rightarrow MnCl_2+Cl_2+2H_2O\)
Ta có:
\(n_{MnO2}=n_{Cl2}=\frac{34,8}{55+16.2}=0,4\left(mol\right)\)
Dẫn hỗn hợp khí vào NaOH
\(m_{NaOH}=291,6.20\%=58,32\left(g\right)\Rightarrow n_{NaOH}=\frac{58,32}{40}=1,458\left(mol\right)\)
\(\Rightarrow n_{NaOH}>2n_{Cl2}\) nên NaOH dư.
\(n_{NaCl}=n_{NaClO}=0,4\left(mol\right)\)
\(n_{NaOH\left(dư\right)}=1,458-0,4.2=0,658\left(mol\right)\)
BTKL:
\(m_{dd\left(A\right)}=m_{dd\left(NaOH\right)}+m_{Cl2}=291,6+0,4.71=320\left(g\right)\)
\(m_{NaCl}=0,4.58,5=23,4\left(g\right)\)
\(m_{NaClO}=0,4.74,5=29,8\left(g\right)\)
\(m_{NaOH\left(dư\right)}=0,658.40=26,32\left(g\right)\)
\(\Rightarrow C\%_{NaCl}=7,3125\%;C\%_{NaClO}=9,3125\%;C\%_{NaOH\left(dư\right)}=\frac{26,32}{320}=8,225\%\)