The pH Scale

[H + ]pHExample Acids 1 X HCl 1 x Stomach acid 1 x Lemon juice 1 x Vinegar 1 x Soda 1 x Rainwater 1 x Milk Neutral1 x Pure water Bases 1 x Egg whites 1 x Baking soda 1 x Tums ® antacid 1 x Ammonia 1 x Mineral lime - Ca(OH) 2 1 x Drano ® 1 x NaOH

Practice  P.239 # 1 – 3

The pH Scale In acidic solutions, [H + ] > 1.0  10 -7, so pH < 7.00 pH = - log [ H + ] [ H + ] = antilog –pH

1) Find the pH value of M HCl solution. HCl (g) + H 2 O (l) → H 3 O + (aq) + Cl - (aq) 0.04 M 0.04 M pH = -log [H 3 O + ] pH = -log [ M] pH = ) Calculate the pH of a mol/L solution of HNO 3(aq). HNO 3(aq) → H + (aq) + NO 3 – (aq) mol/L pH = - log (0.025) = 1.60 pH = -log [H 3 O + ]

3) Find the concentration of H 3 O + if the pH of the solution is 6.47 [ H 3 O + ] = 10 -pH [ H 3 O + ] = [ H 3 O + ] = 3.4 x M

Practice  P.242 # 4 – 8

The pOH Scale In basic solutions, [H+] 7.00 pOH = - log [ OH - ] [ OH _ ] = antilog –pOH

KOH (s) ↔ K + (aq) + OH - (aq) 0.10 mol/L pOH = -log (1.0 x ) pOH = ) Calculate the pOH of a.10 mol/L KOH (aq) solution. pOH = -log (OH - )

2) Calculate the pOH of a mol/L solution of Mg(OH) 2(aq). Mg(OH) 2 (s) → Mg +2 (aq) + 2 OH - (aq) 0.050mol/L 0.10 mol/L pOH = -log (0.10 mol/L) pOH = 1.00 pOH = -log (OH - )

Practice  P.243 # Section 6.2 Questions  P.244 #