Presentation is loading. Please wait.

Presentation is loading. Please wait.

PH and pOH Chem 332 – O’Dette.

Similar presentations


Presentation on theme: "PH and pOH Chem 332 – O’Dette."— Presentation transcript:

1 pH and pOH Chem 332 – O’Dette

2 pH (Potential of Hydrogen)
Measures the degree of acidity or basicity of an aqueous solution Corresponds to the hydrogen ion concentration, [H+] Measured on a scale from 0-14 - pH < 7 → Acid [H+] > 10-7 - pH ≈ 7 → Neutral [H+] = 10-7 - pH > 7 → Base [H+] < 10-7

3 pH Scale Strong Acids Weak Acids Weak Bases Strong Bases Neutral 1 2 3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 Strong Acids Weak Acids Weak Bases Strong Bases Neutral

4 pH of Different Solutions
Bases: Bleach = 13 Soapy Water = 12 Ammonia Solution = 11 Milk of Magnesia = 10 Baking Soda = 9 Sea Water = 8 Acids: Urine = 6 Black Coffee = 5 Tomato Juice = 4 Orange Juice = 3 Lemon Juice = 2 Gastric Acid =1 Neutral: - Distilled Water = 7

5 Calculating pH pH = - log [H+] [H+] = 10-pH Based on a log scale
From [H+] → pH From pH → [H+] pH = - log [H+] Memorize [H+] = 10-pH

6 Step-Through Example Find pH of 0.2 M of Hydrochloric Acid
HCl(aq) → H+(aq) + Cl-(aq) 1 mole mole 1 mole [0.2 M] → [0.2 M] [0.2 M] pH = - log [H+] = - log [0.2M] pH = 0.7

7 pOH (Potential of Hydroxide)
Similar to pH except pOH measures the hydroxide ion concentration, [OH-]

8 Calculating pOH pOH = - log [OH-] [OH-] = 10-pOH From [OH-] → pOH
From pOH → [OH-] pOH = - log [OH-] Memorize [OH-] = 10-pOH

9 Relationship between pH and pOH
pH + pOH = 14 [H+] x [OH-] = 10-14 Memorize

10 Ex: Find the pH of 0.1 M of sulfurous acid, H2SO3
H2SO3 (aq) → 2 H+ (aq) + SO3-2 (aq) 1 mole moles mole [0.1 M] → [0.2 M] [0.1 M] pH = - log [H+] = - log [0.2M] pH = 0.7

11 Ex: Find the pH of 0.005 M of Calcium Hydroxide, Ca(OH)2
Ca(OH)2 (aq) → Ca+ (aq) + 2OH- (aq) 1 mole mole moles [0.005 M] → [0.005 M] + [0.01 M] pOH = - log [OH-] = - log [0.01M] pOH = 2 pH + pOH = 14 pH = 14 – pOH = pH = 12


Download ppt "PH and pOH Chem 332 – O’Dette."

Similar presentations


Ads by Google