If the BaSO4 residue was baked in an oven at 100C for severa

If the BaSO4 residue was baked in an oven at 100C for several hours rather than air drying, what effect would this have on its mass and how would the initial concentration of H2SO4 be affected (higher, lower, or no change)? Explain.

Solution

The reaction will lead to removal of SO3 gas and so mass of BaSO4 will be decreased.

BaSO4 --------------> BaO + SO3

and also the initial concentration of H2SO4 will be decreased due to the following reaction

SO3+ H2SO4 ----------------> H2S2O7