Buffers Concept Check

The pH scale measures...

• ...the strength of an acid.
• ...the strength of hydrogen ions.
• ...the concentration of hydrogen ions.
• ...the concentration of an acid

Buffer is defined as

• ability to resist pH change
• ability to prevent pH from decreasing
• ability to resist a pH increase
• ability to resist pH change when small amount of acid or base is added

What might happen if buffers did not exist within the human body?

• Our blood and other bodily fluids might become too acidic or basic.

• Our stomach acid would not be able to break down food.

• We would not be able to process glucose within our cells.

• We would not be able to inhale oxygen into our lungs.

Tags

NGSS.HS-LS1-3

An acidic buffer is made up of a

• weak acid and weak base
• weak acid and its conjugate salt
• weak acid and its conjugate base
• strong acid and its conjugate base

A basic buffer is made up of a

• weak base and weak acid
• weak base and its conjugate salt
• weak base and its conjugate acid
• strong base and its conjugate acid

Two beakers have liquids in them. When you add a base such as ammonia to beaker 1, the pH did not change. But when you add ammonia to beaker 2, the pH changes drastically. Choose the best explanation.

• Beaker 1 had only water and Beaker 2 contained a buffer.

• Beaker 1 contained a buffer and Beaker 2 contained only water.

• Beaker 2 contained an acid.

• The beaker that changed pH contained a buffer.

Mixtures that would be considered buffers include which of the following?

I. 0.10 M HCl + 0.10 M NaCl

II. 0.10 M HF + 0.10 M NaF

III. 0.10 M HNO₃ + 0.10 M NaNO₃

• I only

• II only

• III only

• II and III

Which solution A and B of equal volume and concentration mixed together to form a buffer?

• Nitric acid and potassium hydroxide
• Nitric acid and potassium nitrate
• Propanoic acid and potassium hydroxide
• Propanoic acid and potassium propanoate

The addition of hydrofluoric acid and __________ to water produces a buffer solution.

• HCl

• NaNO₃

• NaF

• NaCl

Which of the following reactions shows what happens when potassium hydroxide is added to an ammonium ion/ammonia buffer?

• OH^- + NH₃ ⇌ NH₃OH

• K⁺ + NH₃⇌ KNH₃

• K⁺ + NH₄⁺ ⇌ NH₄K

• OH^- + NH₄⁺ ⇌ NH₃ + H₂O

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7