the concentration of HCI
[tex]mass \: formula \: of \: hci = 1 + 35.5[/tex]
[tex] = 36.5[/tex]
[tex]mass = relative \: formula \: mass \times amount[/tex]
[tex] = 36.5 \times 0.125[/tex]
[tex] = 4.56g | {dm}^{3} [/tex]
hence, the concentration of HCI is 4.56g/dm3.