It has something to do with barium chloride being an excess reagent, so that the Cl- present comes from barium chloride.

Will help you later if I have time, but currently I am stuck in a series of classes until 10 pm+.

Give you a clue first: write the balanced equation and perform mole ratio calculations.

Mole ratio of BaCl2 : AgNO3 is 1 : 2.

Okk

BaCl2 + 2 AgNO3 ==> Ba(NO3)2 + 2 AgCl

Mole ratio of BaCl2 to AgNO3 is 1 : 2. Thus means that for every 1 mol of BaCl2 reacted, we need 2 mol of AgNO3.

8 cm3 of a 1 mol/dm3 solution provides 0.008 mol, or 8 milli mole, of the solution.

Basically,
- 8 mmol BaCl2 requires 16 mmol AgNO3,
- 8 mmol AgNO3 requires 4 mmol BaCl2

So it’s clear that when all 8 mmol AgNO3 is reacted, only 4 mmol BaCl2 has been reacted, meaning that there is still 4 mmol unreacted BaCl2.

The final mixture contains 4 mmol BaCl2, 4 mmol Ba(NO3)2 and 8 mmol solid AgCl by the mole ratio.

So, only BaCl2 and Ba(NO3)2 will generate ions.

What about agcl? Why they nvr disociate into ions? Is it cuz agcl is a white ppt and is insoluble in solution. Hence no dissolve then let alone disociation?

The fact that it forms a white precipitate shows that it is unable to dissolve in water. This would mean that they would not dissociate into ions.

Ok understand alr ty