Solution, Acids and Bases Practice 3

Ammonia reacts slightly with water according to NH₃(g) + H₂O(l) → NH₄⁺(aq) + OH⁻(aq). We would expect the resulting solution to be

• acidic

• neutral

• basic

Answer explanation

The additional OH− ions will raise the pH

If 17.6 g of HCl are used to produce a 14.5 L solution, what is the pH of the solution?

A change in pH of 1.0 unit indicates that

• the volume of H⁺ in a solution changes by an order of magnitude.

• the molarity of H⁺ changes by one order of magnitude.

• the salt content decreases or increases by 1.0 M.

• the acid or base content decreases or increases by 1.0 M.

• the acid or base content decreases or increases by 0.1 M.

Answer explanation

If the pH of a solution is 1.0, that means that the H⁺ concentration is 0.1 M. If the pH is 2.0, the H⁺ concentration is 0.01 M. The difference is one order of magnitude.

What is the pH of a 0.010 M solution of H₂SO₄? Consider that both H atoms are completely ionized.

A sample of ____ grams of NaOH are needed to give a pH of 11.5 in a 14.5 L tank of water.

What is the conjugate acid of NO₃⁻?

• HNO₃

• NO₂⁻

• NH₃

• H₂O

In this reaction CH₃NH₂ + H₂O ⇌ CH₃NH₃⁺ + OH⁻, CH₃NH₂ can be classified as (a)  

• a Lewis acid.

• a Bronsted-Lowry acid.

• an Arrhenius acid.

• an oxidizing agent.

• a Bronsted-Lowry base.

Answer explanation

Definition of a Bronsted-Lowry base.

Which reaction may be described as an acid-base neutralization reaction?

• HNO₂ + H₂O → H₃O⁺ + NO₂^-

• NaOH + H₂O → H₃O⁺ + NaO⁻

• Ba(OH)₂ + 2 LiCl → BaCl₂ + 2 LiOH

• Be(OH)₂ + H₂SO₄ → BeSO₄ + 2 H₂O

Answer explanation

Definition of a neutralization reaction

Which of the following cannot exhibit amphoterism?

• H₂O

• OH⁻

• O^2-

• All can exhibit amphoterism.

Answer explanation

Amphoteric species can either accept or donate a proton. O²⁻ can accept a proton, but it has no protons to donate.

A saturated solution of which of the following substances in water would be the best conductor of electricity?

• HCl

• CH₃COOH

• CH₄

• NH₃

• Hg₂Cl₂

Answer explanation

Property of strong electrolytes.