Đặt :
nH2SO4(mp) = x mol
nHCl (mp) = y mol
P1 :
nBaSO4 = 0.03 mol
BaCl2 + H2SO4 --> BaSO4 + 2HCl
_________0.03______0.03
P2 :
nCO2 = 0.04 mol
Na2CO3 + H2SO4 --> Na2SO4 + CO2 + H2O
__________0.03_______________0.03
Na2CO3 + 2HCl --> 2NaCl + CO2 + H2O
__________0.02___________0.04-0.03
nH2SO4 = 0.03 * 2 = 0.06 mol
nHCl = 0.02 * 2 = 0.04 mol
CM H2SO4 = 0.06/0.01=6M
CM HCl = 0.04/0.01 = 4M
P1: H2SO4 + BaCl2--> BaSO4 ↓ + 2HCl
P2: H2SO4 + Na2CO3--> Na2SO4 + H2O + CO2
2HCl + Na2CO3--> 2NaCl + H2O + CO2
Ta có nBaSO4= 6,99/233=0,03 =nH2SO4
=> nH2SO4 ban đầu = 2.0,03=0,06
=> CM ddH2SO4= 0,06/0,01=6M
Ta có nCO2= 0,896/22,4=0,04= nH2SO4 + nHCl/2
= 0,03 + nHCl/2
=> nHCl=0,02
=> nHCl ban đầu= 2.0,02=0,04
=> CM dd HCl=0,04/0,01=4M