The pH Scale

Question 1

What is the equation for pH?

Answer 1

pH = - log [H3O+]

Question 2

What happens when concentration of H+ ions increase?

Answer 2

The pH decreases, meaning the solution is becoming more acidic.

Question 3

What kind of pH do acids and bases have?

Answer 3

Bases = high pH

Acids = low pH

Question 4

What is the equation for finding the concentration of H+ ions?

Answer 4

10^ -pH = [H+]

Question 5

What is an indicator?

Answer 5

Chemicals that change color depending on the [H+] in solution. It is used to identify pH.

Question 6

What is Autoionization?

Answer 6

It is when water acts like an acid or a base in the same reaction. Water transfers a Hydrogen ion to another water molecule.

equation: H2O –> H+ + OH-

Question 7

What is Kw?

Answer 7

Kw is the equillibrrim constant for water. Because of water’s Autoionization ability, at 298 K (standard temperature) the equilibrium constant is always the same.

Kw = [H+] [OH-]
—————
[H20]

Kw = 1.00 x 10^-14

Question 8

What is the equation for pOH?

Answer 8

pOH = - log [OH-]