contestada

Which equations represent precipitation reactions?

Na2S + FeBr2 → 2NaBr + FeS
MgSO4 + CaCl2 → MgCl2 + CaSO4
LiOH + NH4I → LiI + NH4OH
2NaCl + K2S → Na2S + 2KCl
AgNO3 + NaCl → AgCl + NaNO3

Respuesta :

A. : In this reaction one of the product, FeS is insoluble. Therefore, this is a precipitation reaction.


B. : In this reaction, the product is a solid(insoluble). So, this is a precipitation reaction too.


C.: In this reaction, both the products are soluble. So this is not a precipitation reaction.


D.: In this reaction, both the products are soluble. So this is not a precipitation reaction.


E. : In this reaction, the product AgCl is a precipitate. So, it is a precipitation reaction.

Answer : The correct option is, [tex]AgNO_3+NaCl\rightarrow AgCl+NaNO_3[/tex]

Explanation :

Precipitation reaction : It is defied as the chemical reaction in which the two soluble salts solutions combined to form an insoluble salts.

(1) [tex]Na_2S+FeBr_2\rightarrow 2NaBr+FeS[/tex]

(2) [tex]MgSO_4+CaCl_2\rightarrow MgCl_2+CaSO_4[/tex]

(3) [tex]LiOH+NH_4I\rightarrow LiI+NH_4OH[/tex]

(4) [tex]2NaCl+K_2S\rightarrow Na_2S+2KCl[/tex]

(5) [tex]AgNO_3+NaCl\rightarrow AgCl+NaNO_3[/tex]

In the given reactions 1, 2, 3 and 4, the salt forms are completely soluble in water.

As we know that all the sodium, potassium and ammonium salts are soluble in water.

While in the reaction 5, the salt form that is silver chloride (AgCl) are insoluble in water. So, this reaction is a precipitation reaction.

Hence, the correct option is, [tex]AgNO_3+NaCl\rightarrow AgCl+NaNO_3[/tex]