If helium is introduced in a reactor containing O₂, SO₂ and SO₃ at equilibrium, so that total pressure increases while volume and temperature remains constant. In this case the dissociation of SO₃ (as per Le Chatlier principle)

Decreases
Increases
Remains unaltered
Changes unpredictably
✅ The correct answer is option A.

Promoter.

Initiates a chemical reaction and is a catalyst by itself
Atlers the position of equilibrium in a reversible reaction
Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals
All of the above
✅ The correct answer is option C.

Which of the following will favour the reverse reaction in a chemical equilibrium reaction?

Increasing the concentration of one of the reactants
Increasing the concentration of one or more of the products
Removal of at least one of the products at regular interval
None of these
✅ The correct answer is option B.