3 acids bases & salts
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Transcript of 3 acids bases & salts
Module III - Ionic Phenomena
Objectives 2.1 To identify the properties normally
used to classify substances in aqueous solutions as either acids, bases, or salts.
2.2 To determine the conditions under which substances will show the
properties of acids, bases, or salts.
ACIDS, BASES AND SALTS
ACIDS BASES
SALTS
Substances
The word acids comes from one of its characteristic properties, its taste.
ACIDS = “acidus” (latin word) meaning sour.
ACIDSAcids
Bases are substances that are very slippery to touch and have
a strong bitter taste.
BASES Bases
SALTS
Salts are a source of ions that are easily absorbed by living organisms.
They are often used to change the physical properties of various solutions by lowering the
freezing points or raising the boiling points
Salts
ElectricalConductivity
Magnesium Taste/Touch
LitmusPaper
ACID YES Reaction Sour Turns red
BASE YES No ReactionBitter/
Slippery Turns Blue
SALT YES No Reaction SaltyDepends on the solution
Electrolytes – solutions that conduct electricity
Properties of Acids, Bases and Salts
Litmus paper is a type of indicator(thin strip of paper that is dipped into a solution)
2 Types: Blue Litmus Paper Red Litmus Paper
ACIDS – Turn blue litmus paper red
BASES – Turn red litmus paper blue
(USED TO DETECT ACIDS OR BASES)
BB
SALTS – not all salts are neutral - can be either acidic or basic (test with litmus paper)
Indicators
Phenolphthalein is another type of indicator
Bases turn clear phenolphthalein pink
Indicators
Chemically neutral – means does not contain an acid or
base
“Making a solution chemically neutral”
Neutralize it with a base
Neutralize it with an acid
Acids and bases neutralize each other forming a salt and waterEx. Acid + Base = Salt + water
Acids, bases and salts conduct electricity
Tap water -will conduct
-(free ions around)
Distilled water -does not-conduct
-(no free ions!)
o Review chart: (very important!)Electrical
ConductivityMagnesium Taste/
TouchLitmusPaper
ACID YES Reaction Sour Turns red
BASE YES No ReactionBitter/
Slippery Turns Blue
SALT YES No Reaction SaltyDepends on the
solution
Worksheet # 1 Study guide, Module 3, page 2
References
Science Quest, Grenier,Daigle & Rheaume, 1998
Physical Science Student Study Guide 416-436
Animation Factory Google Images