Theory

The Gravimetric Estimation of Barium:

The given barium chloride solution is made up to a definite volume. A measured volume of it is then treated with dilute sulphuric acid and then treated with dilute sulphuric acid and barium precipitated as barium sulphate.

$$BaCl_2+H_2SO_4\to BaSO_4+2HCl$$

The precipitated barium sulphate is separated and weighed. The mass of Barium in the whole of the given solution is calculated knowing that 233.36 g of barium sulphate contains 137.36 g of barium.

Note: For more details refer the theory of "Gravimetric Estimation of Nickel."