Answer: The concentration of sulfate ions in the solution is

Step-by-step explanation:
To calculate the number of moles for given molarity of solution, we use the equation:
.......(1)
For barium ions:
Molarity of solution = 0.00100 M
Volume of solution = 5.00 mL
Putting values in equation 1, we get:

The chemical equation for the ionization of barium sulfate follows:

By Stoichiometry of the reaction:
1 mole of barium ions precipitate 1 mole of sulfate ions
So,
moles of barium ions will precipitate
moles of sulfate ions
Now, calculating the molarity of sulfate ions by using equation 1:
Moles of sulfate ions =
moles
Volume of solution = 56.1 mL
Putting values in equation 1, we get:

Hence, the concentration of sulfate ions in the solution is
