Question

Q. What happens when an aqueous solution of sodium sulphate reacts with an aqueous solution of barium chloride? Write the balanced chemical equation for the reaction. State the physical conditions of reactants in which the reaction between them will not take place. [CBSE, 2010]
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Answer 1

Answer:

Solution:

In this question, we are given the reactants. Let us first write down their formulae and states correctly.

Sodium sulphate: Na2SO4 (aq)

Barium chloride: BaCl2(aq)

We write down (aq) as we are given that both the compounds are in solution form. So the reaction will start like: Na2SO4(aq) + BaCl2(aq)

Now if you remember, these substances react together to give a double displacement reaction: Na2SO4 (aq) + BaCl2 (aq) BaSO4(s)+ 2NaCl (aq)

And during the reaction, a white precipitate of BaSO4 is formed.

Now, the physical conditions in which no reaction will take place, will be solid – i.e., if both our reactants are in solid form instead of aq, no reaction will be observed.

Answer 2

Answer:

A white ppt. ( precipitate ) is formed.

Na₂SO₄ ( aq ) + BaCl₂ ( ag ) ⇒  2 NaCl ( aq ) + BaSO₄ ( ↓ )

Doubled Displacement reaction

The reaction in which there is an exchange of ions between the reactants.