1. Acids and Bases • compounds that form acids or bases • molecular
Compounds can be:
• ionic
• molecular
• compounds that form acids or bases
Write definition of ionic and molecular compound on your vocab sheet

2. What are acids and bases?
When dissolved in water, acids and bases form solutions that conduct electricity
They are called ELECTROLYTES: compounds that conduct an electrical current when melted or dissolved in water
Write definition of electrolyte and non-electrolyte on your vocabulary sheet

3. Acids Svante Arrhenius (1884) suggested that:
Acids = substances that release hydrogen ions, H+ (aq) , in water.
EX. Hydrogen chloride gas dissolved in water yields H+
HCl (g)  H+(aq) + Cl- (aq
Is H+ a cation or an anion???
What does (aq) mean?

4. Acids • We call this solution HCl (aq) hydrochloric acid because
it releases H ions (H+) in solution
main digestive acid in your stomach
Write the definition of an acid on your vocab sheet

5. Bases
Arrhenius proposed that bases are substances that release OH- ions when dissolved in water.
EX. Sodium hydroxide dissolves in water and releases OH-
NaOH(s)  Na+(aq) + OH-(aq)
Is OH- an anion or a cation?

6. Bases
We call this base NaOH(aq) sodium hydroxide Write the definition for base on your vocab sheet

7. Common Acids and Bases Look on page 63 in your text
Acids and bases all have safety warnings – they can react strongly and harm your skin, eyes, and lungs
Safety in the lab is of utmost importance

8. Important Acids and Bases
Read pg in your text and fill in the top half of your
“Acids/Bases Nomenclature” notes sheet

9. The power of hydrogen (pH)
pH is a measure of the strength of an acid or base
We use the pH scale to show the power of H+ of an acid or base (see p. 65 text)
On your “Acids and Bases” notes sheet, draw the pH scale
Add labels
Indicate strong acids (pH 0 – 3), weak acids (pH 4 – 6), neutral (pH 7), weak base (pH 8 – 10), and strong base (pH 11 – 14)

10. How powerful is a pH?
pH scale allows chemists to express a wide range of hydrogen ions and hydroxide ions because pH numbers are EXPONENTS
An acid of pH 1 has more H+ ions/litre than an acid of pH 6!
A base of pH11 has 1000 more OH-/litre than a base of pH 8

11. How do we tell the acidity or alkalinity of an acid or base?
2 ways :
Indicators (remember bromothymol blue and the water plant experiment?), have you ever used litmus paper?
pH meters
Using pg. 65 and 66 in your text, complete the front page of “Acids and Bases” notes sheet, and vocab through “neutral solution”

12. Acid Base Lab Test the acids and bases in the depression wells.
Place a few drops of the solutions in the depression wells. DO NOT mix the droppers!!!!
Test the conductivity of each solution using the conductivity meters (enter yes or no in the table)- rinse well and dry after each use.

13. Acid/Base Lab
Test the pH of each solution using the 3 different indicatory papers and a few drops of phenolpthalein solution and the bromothymol blue – record the color of the indicator in the acid or alkaline solution in your table.
BB = blue pH > 7.6
yellow ph <6
green = neutral
With the universal (pH) paper – indicate color and pH using the scale provided.
Dispose in waste beakers, rinse with tap water, dry
BE SAFE! These are acids and bases!

14. What You Are Testing Baking soda Bleach Hydrochloric acid Vinegar
Lemon juice
Orange juice
Apple juice
Tea
Coffee
Coke
Distilled H2O
Sodium hydroxide

15. What you tested Baking soda! Sodium bicarbonate: NaHCO3
Bleach! Sodium hypochlorite: NaClO:
Hydrochloric acid HCl
Vinegar! Acetic acid: CH3COOH
Lemon juice citric acid C6H8O7 (0.3 mol/L)
Orange juice citric acid C6H8O7 (0.005 mol/L)
Apple juice malic acid
Tea
Coffee
Coke
Sodium hydroxide NaOH

16. pH of common drinks