Chemistry Test Acids and Bases 2

Question 1

Which of the following best describes a Lewis acid?

Accepted Answer

An electron pair acceptor

Answer

A Lewis acid accepts an electron pair from a Lewis base to form a coordinate covalent bond.

Question 2

What is the conjugate base of H₂SO₄?

Accepted Answer

HSO₄⁻

Answer

H₂SO₄ loses one proton to form HSO₄⁻, its conjugate base.

Question 3

A buffer solution resists changes in pH because it contains:

Accepted Answer

A weak acid and its conjugate base

Answer

A buffer contains a weak acid and its conjugate base, which can neutralize added acids or bases.

Question 4

At 25°C, what is the pOH of a solution with [OH⁻] = 1×10⁻³ M?

Accepted Answer

3

Answer

pOH = -log[OH⁻] = -log(1×10⁻³) = 3.

Question 5

Which indicator would be most appropriate for titrating a strong acid with a strong base?

Accepted Answer

Either methyl orange or phenolphthalein

Answer

Strong acid–strong base titrations have a steep equivalence point, so both methyl orange and phenolphthalein are suitable.

Chemistry Practice Test