pH and Indicators Chemistry Mrs. Coyle

Basic 14>ph>7 Neutral ph=7 Acidic 1<pH<7

Self Ionization of H 2 O H 2 O  H + (aq) + OH - (aq) Ion Product Constant K w for Water: K w = [H + ] x [OH - ] =1.0 x

For pure H 2 O [H + ] = [OH - ] = 1.0 x M

pH 1909 Soren Sorensen (Danish) pH=-log[H + ] What is the pH of pure water?

Ex 1: Find the pH for [H + ]=10 -3 M Answer: pH=3

Ex 2: Find the pH for [H + ]=5x10 -3 M Answer: pH=2.3

Finding [H + ] from pH [H + ]= 10 -pH

Ex 3: Find the [H + ] for pH=5 Answer: [H + ] = M

Ex 4: Find the [H + ] for pH=5.8 [H + ]= 10 -pH Answer: [H + ] = 1.6x10 -6 M

pOH pH=-log[H + ] pH + pOH=14

Basic(Alkaline) Solutions Acidic Solutions Neutral Solutions

Acids Change phenolphthalein to colorless.

Acids Turn litmus paper from blue to red.

Bases Change phenolphthalein to pink.