Question

Predict whether each of the following reactions will occur in aqueous solutions. Explain your reasoning in each case. Note: Barium sulfate and silver bromide precipitate in aqueous solutions.
(a) sodium hydroxide + ammonium sulfate → ?
(b) niobium(V) sulfate + barium nitrate → ?
(c) strontium bromide + silver nitrate → ?

Answer 1

Answer: A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

a) sodium hydroxide + ammonium sulfate :

$2NaOH(aq)+(NH_4)_2SO_4(aq)\rightarrow 2NH_4OH(aq)+Na_2SO_4(aq)$

b) niobium(V) sulfate + barium nitrate:

$(Nb)_2(SO_4)_5(aq)+5Ba(NO_3)_2(aq)\rightarrow 2Nb(NO_3)_5(aq)+5BaSO_4(s)$

c) strontium bromide + silver nitrate:

$Sr(Br)_2(aq)+2AgNO_3(aq)\rightarrow Sr(NO_3)_2(aq)+2AgBr(s)$

Answer 2

(a) sodium hydroxide + ammonium sulfate --> sodium sulfate + ammonium hydroxide

sodium sulfate precipitates in aqueous solutions

(b) niobium(V) sulfate + barium nitrate →  Barium sulfate + niobium nitride

both do not precipitate in aqueous solution

(c) strontium bromide + silver nitrate ---> strontium nitrate + silver bromide

both  do not precipitate in aqueous solution