Chapter 25 - Acids and Bases

Key Terms:

Objectives of chapter:

• identify acids, bases and salts
• understand acid/ base as a behavior of chemicals
• identify the hydroxide and hydronium ions
• recognize salt as a product of the reaction of an acid and a base
• understand what is meant by acidic, basic and neutral
• describe and explain the concept of pH
• apply the concepts of acids and bases to our atmosphere and ocean

Outline:

25. 1 Define and describe Acids and Bases

Acids: donate protons (give off H+ when dissolved in water)

taste sour, are electrolytes, are corrosive, react with certain compounds called indicators to produce color changes, can be used to make fertilizer

Bases : accept protons (give off OH-)

the other half of the water molecule, taste bitter, are corrosive, feel slippery, react with certain compounds called indicators to produce color changes

 

list some of the common acids

name	formula	where found
acetic acid	.	vinegar
acetylsalicylic acid	.	aspirin
boric acid	.	eyewash solutions
carbonic acid	.	carbonated beverages
nitric acid	.	fertilizer
phosphoric acid	.	fertilizer
sulfuric acid	.	car batteries, lots of stuff
hydrochloric acid	.	stomach acid
.	.	.

list some of the common bases

name	formula	where found
aluminum hydroxide	.	deodorant
calcium hydroxide	.	leather production
magnesium hydroxide	.	laxative, antacid
sodium hydroxide	.	drain cleaner
ammonia	.	household cleaner
.	.	.

25.2 Strength of Acids and bases

how readily an acid donates its proton determines its strength

• define pH : A measure of the hydronium atoms in solution
  the smaller the number the more acid a solution
  the greater the number the more basic a solution
  a pH scale
  this scale is logarithmic, so each step is a factor of 10.
• a pH meter
• an interesting explanation of how indicators work water to wine

how corrosive something is determined by how many H3O+ ions are generated.

see interactive tutorial 25.2

25.3 Solutions can be acidic, basic or neutral

describe neutralization

• a chemical reaction between an acid and a base that results in a salt and water
• these reactions are ionic, powerful and often exothermic

explain a salt

• salts are a compound that is formed by the combination of a metal and a non metal
• they can also occur when acids come into contact with metals
• they contain an ionic bond
• organic salts are soaps , they are made by reacting fats with bases

25.4 Rainwater is Acidic and ocean water basic - naturally

acid rain - what creates it?

how does the ocean absorb greenhouse gases?

Chapter links

caves created by acids

carlsbad and mammoth caves

epa site about acid rain

climate monitoring at Mauna Loa site

class text - conceptual physical science

PCDS useful links - sorted by topic

 

Related labs, activities and videos

difficult decisions - acid rain

cabbage juice

pH with vernier probes

upset stomach - titration

Practice Book Exercises

donating and accepting hydrogen ions - page 97

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