Acids, Bases and pH

Question 1

Acid produces H+ when dissolved in water. What does a base produce?

Answer 1

• Produces OH- and a cation in water

Question 2

Acid is a H+ Donor and a base is a H+ _____

Answer 2

• Acceptor

Question 3

A base is an electron-pair diner and an acid is an ……..

Answer 3

• Electron-pair acceptor

Question 4

State a acid-base neutralisation reaction

Answer 4

acid + base = salt (+ water)

Question 5

For a strong base, the H+ cation of the acid combines with……

- What does this form?

Answer 5

• The OH- of the base to form water

Question 6

The compounds formed by the cation of the base and the anion of the acid is called a ……

Answer 6

• Salt

Question 7

What does the H+ of acid get replaced with?

Answer 7

• Metal ions

Question 8

For NH3 what is the donor

and acceptor?

Answer 8

Lone pair donor base: N

Lone pair acceptor acid: H+

Question 9

Acids are related to B____

Answer 9

• Bases

e.g acid ——-> proton + conjugate base

Question 10

Strength is not the same as C_______

Answer 10

• Concentration

Question 11

Strength
• Strong = ?
• Weak = ?

Answer 11

Strong: full dissociation
Weak: partial dissociation (an equilibrium)

Question 12

What concentration is pH a measure of?

Answer 12

• H+

usually very small in living cells

Question 13

Increasing base strength increases…..

Increasing acid strength increases….

Answer 13

• Kb and Ph increase

* Ka and [H3O+] increase

Question 14

Indicators are weak acid molecules which change C_____ with a change of the E_______ P______

Answer 14

• Colour

* Equilibrium Position

Question 15

Acid and basic function groups
• The charge on a molecule and which groups are pronated depends on the pH of surroundings
What does this affect?

Answer 15

• Affects solubility and drug absorption e.g amino acids

Question 16

How can the percentage of ionisation be calculated?

Answer 16

Using the Henderson- hasslebalch equation

pH = pKa + log ([A-]/[HA])

Question 17

If pH < pKa the functional group is

more P_____ than Un______

Answer 17

• Protonated

* Unprotonated

Question 18

If pH > pKa the functional groups is more…….

Answer 18

• Deprotonated than protonated

Question 19

If pH = pKa the functional group is…..

Answer 19

50: 50
protonated: unprotonated

Question 20

What is the function of a buffer?

Answer 20

• A buffer solution resits changes in pH upon the addition of small amounts of either acid or base

Question 21

Name examples of buffers in the body

Answer 21

Buffer systems:

• Blood: bicarbonate (for metabolic acids)
• Urine: phosphate
• Bone: carbonate and phosphate

Question 22

What can be found in erythrocytes to maintain pH of the blood?

Answer 22

• Haemoglobin