Question

Enter a balanced net ionic equation to describe the reactions indicated. Enter NR if no reaction occurred.

Suppose you determine a pH of 0 to 1 for an unknown solution. When mixed in equal volumes, which of the following solutions could have generated an unknown solution consistent with this pH measurement?

a) NH₄Br and AgNO₃

b) CuSO₄ and BaCl₂

c) LiOH and HCl

d) HCl and NH₄Br

e) K₂CO₃ and Na₂S

Answer 1

Net ionic reactions are written for those whose products gives solid precipitates.

a) Ag⁺(aq) + Br^- (aq)---------------------> AgBr(s)

b) Ba²⁺(aq) + SO₄^2-(aq) -------------------> BaSO₄(s)

c) NR

d) NR

e) NR

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The pH of the resultant solution is given as 0 to 1 which means it should be strongly acidic solution. Only the the mixture of HCl and NH₄Br produces the pH shown/ required. Since the Hydrobromic acid produced in option d is very strong acid.

HCl(aq) + NH₄Br(aq) -------------------------> HBr(aq) + NH₄Cl (aq)

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The rest of the mixtures produces insignificant inorganic salts which are not capable enough to yield a an unknown solution of pH 0 to 1

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The option c can be a neutral solution , since it is a combination of base and acid.

The option e can be a basic solution.

options a and b are insignificant in yielding acidic solutions of pH range 0 to 1