Respuesta :
The chemical equations representing the reaction between the given combinations are:
1. [tex]CaS(aq) + Na_{2}SO_{4}(aq)-->CaSO_{4}(s)+Na_{2}S(aq)[/tex].This reaction is a precipitation reaction as one of the product formed, CaSO[tex]_{4}[/tex] is a solid.
2. [tex]Li_{2}SO_{4}(aq)+2KOH(aq)-->K_{2}SO_{4}(aq)+2LiOH(aq)[/tex] In this reaction all the products are aqueous or soluble in water.
3.[tex]Li_{2}CO_{3}(aq)+2NaI(aq)-->Na_{2}CO_{3}(aq)+2LiI(aq)[/tex]. Both the products of this reaction are soluble in water.
Hence, the correct option would be 1. CaS + [tex]Na_{2}SO_{4}[/tex]
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:
[tex]CaS(aq)+Na_2SO_4(aq)\rightarrow CaSO_4(s)+Na_S(aq)[/tex]
(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:
[tex]Li_2SO_4(aq)+2KOH(aq)\rightarrow 2LiOH(aq)+K_2SO_4(aq)[/tex]
(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:
[tex]Li_2CO_3(aq)+2NaI(aq)\rightarrow 2LiI(aq)+Na_2SO_4(aq)[/tex]
Hence, the pairs of aqueous solutions form a precipitate when mixed will be, CaS + Na₂SO₄
