Đáp án:
Giải thích các bước giải:
`a.`
`m_{Ba(OH)_2}=40.34,2%=13,68(g)`
`n_{Ba(OH)_2}=(13,68)/171=0,08(mol)`
`Ba(OH)_2+Na_2SO_4->BaSO_4↓+2NaOH`
`n_{Na_2SO_4}=n_{Ba(OH)_2}=0,08(mol)`
`m_{Na_2SO_4}=0,08.142=11,36(g)`
`m_{ddNa_2SO_4}=11,36:14,2%=80(g)`
`b.`
`n_{BaSO_4}=n_{Ba(OH)_2}=0,08(mol)`
`m_{BaSO_4}=0,08.233=18,64(g)`
`c.`
`m_{ddspư}=40+80-18,64=101,36(g)`
`n_{NaOH}=2n_{Ba(OH)_2}=0,16(mol)`
`m_{NaOH}=0,16.40=6,4(g)`
`C%_{ddspư}=(6,4)/(101,36).100=6,314%`