Lecture 2

Question 1

What is pH?

Answer 1

A measure of concentration of H+ in solution

Question 2

At pH 7…

Answer 2

• Pure water
• [H+] is 10^-7
• 1 water molecule per 55 million will be protonated
• At pH 1, 1 water molecule per 55 is protonated

Question 3

What is dynamic equilibrium

Answer 3

When a system’s forward and reverse reactions occur at equal rates. The concentrations of reactants at each side do not change with time.

Question 4

What are acids?

Answer 4

• can lose an H+ ion
• Become negatively charged

Question 5

Does a change in pH affect equilibrium?

Answer 5

Change in pH = Change in [H+] so equilibrium is changed

Question 6

What is le Chatelier’s Principle

Answer 6

If an equilibrium is disturbed by a change of environment (temp conc or pressure) the system tends to shift its equilibrium to counteract the effect of the change.

Question 7

Le chatelier’s principle with acids

Answer 7

Question 8

Relationship between pH and ionisation of acid

Answer 8

Question 9

Ka and pKa

Answer 9

Question 10

Henderson Haelbach equation and % compound ionised equation

Answer 10

Charge term is always -1 for an acid, +1 for a base

Question 11

Le Chatelier’s principle with conjugate acids and bases

Answer 11

Question 12

What is a base

Answer 12

Can reversibly form covalent bonds with an H+ ion to become positively charged (positively ionised)

Question 13

Le Chatelier’s principle with bases

Answer 13

Question 14

Why does this all matter?

Answer 14

If pH changes in body, ionisation of compounds changes, protein conformation changes