Physical Science 1 Chapter 23 Acids Bases & Salts
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Transcript of Physical Science 1 Chapter 23 Acids Bases & Salts
Physical Science 1Chapter 23 Acids Bases & Salts
Properties of Acids• A solution that produces H3O+, hydronium ion, when dissolved in water (H+ ions)• Acid comes from the Latin word acidus meaning "sharp".• pH range 0 – 6.9 • Acids taste sour• Acids are corrosive to metals• Acid will change blue litmus paper red
H
HH H H
H
ClClO O
–+
acid hydromium ion
The strength of an acid
• Strong acids – An acid that totally ionizes in an
aqueous solution. • That means every molecule
breaks apart
– Acid with a very low pH (0 – 4)
• Weak acids – An acid that only partially
ionizes in an aqueous solution. • That means not every
molecule breaks apart.
– They usually have a pH close to 7 (3-6).
- + - +
Properties of Bases• A solution that has an excess of OH- ions• Another word for base is alkali.• pH range 7.1 – 14• Bases taste bitter• Bases feel slippery• Base will change red litmus paper blue
H
H
HH H
H
N NO O–+
HH
H H
hydroxide ionbase
pH Scale• In 1909, the Danish
biochemist Sören Sörensen invented the pH scale for measuring acidity.
• The scale range is from 0 -14– Acids 0 – 7– Neutral 7.0
– Bases 7 – 14
[H+] pH Example
Acids
1 X 100 0 HCl
1 x 10-1 1 Stomach acid
1 x 10-2 2 Lemon juice
1 x 10-3 3 Vinegar
1 x 10-4 4 Soda
1 x 10-5 5 Rainwater
1 x 10-6 6 Milk
Neutral 1 x 10-7 7 Pure water
Bases
1 x 10-8 8 Egg whites
1 x 10-9 9 Baking soda
1 x 10-10 10 Tums® antacid
1 x 10-11 11 Ammonia
1 x 10-12 12 Mineral lime - Ca(OH)2
1 x 10-13 13 Drano®
1 x 10-14 14 NaOH
Indicators• Organic substance whose
solution change color due to changes in pH
• The color of the hydrangea flower depends on the pH of the soil in which it is grown– Blue flowers are produced
in basic soil – Pink flowers are generated
in acidic soil
RED CABBAGE JUICE
Neutralization• ACID + BASE → WATER + IONIC SALT
• H-anion + cation-OH → H2O + Salt (CationBASE AnionACID)
• Equivalence point – when the neutralization is finished• neutralization animation• Examples
– NaOH (aq) + HCl (aq) → NaCl (aq) + H2O (l)
– KOH (aq) + HBr (aq) → KBr (aq) + H2O (l)
• acids & bases with indicator
• The Rainbow Connection Demonstration
• AUSD Classlink