Buffers

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 added

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

Acidic buffer is made up of

• weak acid and weak base

• weak acid and its conjugate salt

• weak acid and its conjugate base

• strong acid and its conjugate base

When making a buffer of pH = 5, acids with the following K_a values are available. Which would be the best acid to use?

• 1.8 x 10^-5

• 1.8 x 10^-8

• 4.9 x 10^-10

• 3.0 x 10^-8

A buffer has a pH of 4.85 and contains formic acid and potassium formate. What can you conclude about the concentrations of the components of the buffer? The K_a of formic acid is 1.8 x 10^-4.

• Formic acid > Potassium formate

• Formic acid < Potassium formate

• Formic acid = Potassium formate

• More information is needed to determine the relative concentrations

What is the pH of a buffer that is 0.08 M NaA and 0.1 HA. The Ka of HA = 1.0 x 10^-4.

• 2.16
• 3.91
• 4.00
• 4.10
  

Suppose you have a solution of 0.3 M HBrO and 0.3 M BrO. You add a small amount of NaOH to this buffer solution. What is the reaction that takes place?

• H⁺ + BrO^- --> HBrO

• OH^- + H⁺ --> H₂O

• OH^- + HBrO --> H₂O + BrO^-

• OH^- + BrO^- --> O^-2 + HBrO

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