Biology pH and Buffers

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

• Hydrochloric acid
• cabbage
• milk

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

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

Basic buffer is made up of

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

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

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