Which of the following pairs of aqueous solutions will form a precipitate when mixed? which of the following pairs of aqueous solutions will form a precipitate when mixed? cas + na2so4 li2so4 + koh li2co3 + nai none of these solution pairs will produce a precipitate. all of these solution pairs will produce a precipitate.

Answer : The pairs of aqueous solutions form a precipitate when mixed will be, CaS + Na₂SO₄

Explanation :

Precipitation reaction : It is defined as the reaction in which an insoluble salt formed when two aqueous solutions are combined.

The insoluble salt that settle down in the solution is known an precipitate.

(a) CaS + Na₂SO₄

When aqueous solution of calcium sulfide react with aqueous solution of sodium sulfate then it gives insoluble salt of calcium sulfate and aqueous solution of sodium sulfide.

The insoluble salt that is calcium sulfate is a precipitate.

The balanced chemical reaction is:

(b) Li₂SO₄ + KOH

When aqueous solution of lithium sulfate react with aqueous solution of potassium hydroxide then it gives aqueous solution of lithium hydroxide and potassium sulfate. There is no formation of precipitate.

The balanced chemical reaction is:

(c) Li₂CO₃ + NaI

When aqueous solution of lithium carbonate react with aqueous solution of sodium iodide then it gives aqueous solution of lithium iodide and sodium sulfate. There is no formation of precipitate.

The balanced chemical reaction is:

Hence, the pairs of aqueous solutions form a precipitate when mixed will be, CaS + Na₂SO₄

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .