pH and Buffer

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

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

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 only

• II only

• III only

• II and III

The pH of the body fluids is stabilised by buffer systems, which of the following is the most effective buffer system at physiological pH?

• Protein Buffer

• Bicarbonate buffer

• Heemoglobin buffer

• Phosphate buffer

Tags

NGSS.HS-LS1-3

Which of the following is true about acids and bases?

• The lower the pH, the stronger the acid

• the higher the pH, the stronger the acid

• The lower the pH, the more neutral the acid

• The higher the pH, the weaker the base

The pH scale measures...

• ...the strength of an acid.

• ...the strength of hydrogen ions.

• ...the concentration of hydrogen ions.

• ...the concentration of an acid

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

According to the pH range which substance is more acidic than lemon juice

• Hydrochloric acid

• cabbage

• milk

Tags

NGSS.MS-PS1-2

Why do cells need a buffer system?

• Chemical processes in the cell are sensitive to the concentration of H⁺ and OH^-

• Cells do not have a buffer system

• Cells need acids and bases to survive

• The pH range of cells can withstand large changes