pH and Buffer

Human blood has a pH between 7.35 and 7.45. Which of the following best describes human blood?

• strongly acidic

• slightly acidic

• strongly basic

• slightly basic

Tags

NGSS.HS-LS1-3

Why were the biological samples generally good buffers?

• Water is a poor buffer

• They need to maintain a pH of 8.0 at all times

• All living organisms need to maintain homeostasis in terms of pH

• The samples came in liquid form

Tags

NGSS.HS-LS1-3

Which type of ion does a base produce when it is dissolved in water?

• oxide

• oxygen

• hydrogen

• hydroxide

How does a buffer solution resist changes in pH?

• By increasing the temperature of the solution

• By changing color when pH shifts

• By containing a weak acid and its conjugate base (or a weak base and its conjugate acid), the buffer solution can neutralize added acids or bases, preventing drastic changes in pH.

• By releasing more ions into the solution

Describe the buffer range of a buffer solution.

• Buffer range refers to the color range of a buffer solution

• The buffer range is the temperature range at which a buffer solution is most effective

• Buffer range is the concentration range of the buffer components in a buffer solution

• The buffer range of a buffer solution is the pH range over which the buffer effectively resists changes in pH when small amounts of acid or base are added.

What happens to the pH of a buffer solution when a small amount of acid is added?

• The pH of a buffer solution will significantly increase.

• The pH of a buffer solution will fluctuate randomly.

• The pH of a buffer solution will remain the same.

• The pH of a buffer solution will only slightly decrease.

How does a buffer system work to maintain pH?

• A buffer system works by having a weak acid and its conjugate base or a weak base and its conjugate acid in equilibrium. When an acid or base is added, the buffer components react with it to prevent drastic changes in pH.

• A buffer system works by completely neutralizing any added acid or base.

• A buffer system works by converting all acids and bases into neutral compounds.

• A buffer system works by releasing excess acid or base to maintain pH balance.

What is the pH of a buffer solution composed of equal concentrations of a weak acid and its conjugate base?

• pH of the conjugate base

• pH of a strong acid

• pH of the weak acid

• pKa of the weak acid

How does a buffer system minimize pH changes upon addition of acid or base?

• A buffer system has no effect on pH changes upon addition of acid or base

• A buffer system minimizes pH changes upon addition of acid or base by neutralizing them through the presence of a weak acid and its conjugate base or a weak base and its conjugate acid.

• A buffer system maximizes pH changes upon addition of acid or base by amplifying them

• A buffer system causes drastic pH changes upon addition of acid or base

Define basic solutions in terms of pH.

• Basic solutions have a pH between 5 and 7.

• Basic solutions have a pH of exactly 7.

• Basic solutions have a pH less than 7.

• Basic solutions have a pH greater than 7.