2.  pH: The negative of the common logarithm of the hydronium ion concentration [H 3 O + ] ◦ pH stands for the French words pouvoir hydrogene, meaning “hydrogen power”  pH = -log [H 3 O + ] ◦ A neutral solution at 25°C (room temperature) has a [H 3 O + ] of 1x10 -7 M ◦ pH = -log [H 3 O + ] = -log (1x10 -7 ) = -(-7) = 7

3.  pOH: The negative of the common logarithm of the hydroxide ion concentration [OH - ]  pOH = -log [OH - ] ◦ A neutral solution at 25°C has a [OH - ] of 1x10 -7 M ◦ pOH = -log [OH - ] = -log (1x10 -7 ) = -(-7) = 7  pH + pOH = 14

4.  What is the pH of a 1.0x10 -3 M HCl solution? ◦ pH = -log (1.0x10 -3 ) = 3 ◦ The pH is 3!  What is the pOH of a 1.0x10 -3 M HCl solution? ◦ Because HCl is an acid, we must first find pH  pH = -log (1.0x10 -3 ) = 3 ◦ To find pOH we need to subtract pH from 14  14 – pH = pOH  14 – 3 = 11  pOH is 11!

5.  What is the pH of a 1.0x10 -3 M NaOH solution? ◦ Because NaOH is a base, we must first find pOH.  pOH = -log (1.0x10 -3 ) = 3 ◦ To find pH we need to subtract pOH from 14.  14 – pOH = pH  14 – 3 = 11  The pH is 11!