Note Guide 5-1 – Acids and BasesIdentifying Acids

--acid is a compound that produces hydronium ions (H30+) when dissolved in water.--Properties of acids include

1. Sour taste: foods like lemons, grapefruits, limes contain citric acid. Vinegar contains acetic acid2. Reactivity with metals: aluminum foil can react with the citric acid from a tomato.

--reaction between an acid and a metal is an single-replacement reaction (chemical reaction in which one element takes the place of another element in a compound

Zn + 2HCl H2 +ZnCl2

Means reacts to produce

3. Color changes in Indicators Indicator – is any substance that changes color in the presence of an acid or base

Ex: Litmus paper

--blue litmus paper turns red when in acid so, if an unknown solution is placed on blue

litmus paper and it turns red, its an acid.Common Acids

--acetic acid – vinegar

--carbonic acid – Carbonated beverages

--Nitric acid – Fertilizer

--Sulfuric acid – Car batteries

Properties of Bases include1. Bitter taste: unsweetened chocolate, cough syrups, etc

2. Slippery feel: wet soap, cleaning products;

Identifying Bases

--Base= compound that produces hydroxide ions (OH-) when dissolved in water

NaOH Na+ + OH-

3. Color changes: turns red litmus blue

--so if an unknown solution turns a piece of red litmus blue, it’s a base

Common bases:

--Aluminum hydroxide = deodorant, antacid

--Calcium hydroxide = concrete, plaster

--Magnesium hydroxide = antacid, laxative

Neutralization and Salts:

--A reaction between an acid and a base is called neutralization--basically cancels each other out.--negative ions from acid combine with positive ions of base to produce ionic compound called salt

--the neutraliztion reaction between an acid and a base produces a salt and water

(H3O++ Cl-) + (Na+ + OH-) 2H20 + (Na+ + Cl-)

(acid) (base) (water) (salt)Common Salts

--sodium chloride = food flavoring

--Magnesium chloride = de-icer for roads

--Calcium carbonate = chalk, marble floors, and tables

--Ammonium nitrate = fertilizer, cold packs

Note Guide 5-2 Strength of Acids and bases

--How can you describe the acidity or basicity of a solution?By using a number scale from 0 to 14 to describe the concentration of hydronium ions (H3O+) in a solution. This scale is the pH scale.The pH measure how much hydronium ions are in the solution--if a solution measure to a 7, then it is neutral (not acid or base)--if a solution measures over a 7, it is a base

--if a solution measures under a 7, it is an acid –see figure 22 on page 247

So what does this mean in regard to hydronium concetration?--the lower the pH value, the greater the H3O+ ion concentration in solution--the higher the pH value, the lower the H3O+ ion concentration in solution.

Strong Acids and Bases

--when acids almost completely ionize (most molecules ionize) when dissolved in water, they are strong acids.

--sulfuric and nitric acids-- when bases dissociate (seperation of ions as they dissolve) almost completely in water, they are considered strong bases.

Weak acids and bases--weak acids and bases ionize (acids) or dissociate (bases) only slightly in water

Weak Acids = citric acid in OJ and acids in vinegar

Weak Bases = toothpase and shampoo

Concentration vs. Strength…the same right?

NO!--concentration is amount of solute (substance whose particles are dissolved in a solution) dissolved in a given amount of solution

--strength is the solute’s tendency to form ions in water.Do not assume that strong acids have a low pH because concentration also affects pH

Buffers = solution that is resistant to large changes in pH.

--Weak acids and bases are used to make buffers--Why does this work? Because the buffer reacts with both the acid and base, keeping the pH relatively constant

Electrolytes: substance that ionizes or dissasociates into ions when it dissolves in water

--sports drinksHow do they work? Restore the balance of ions in body

Strong acids and bases are strong electrolytes because they dissociate or ionize almost completely

--salts are strong electrolytes

--batteries produce electricity which contain electrolytes

--fuel cells

pH scale

Note Guide 5-3 day 1

--if a compound contains carbon and hydrogen we call it an organic

compound. They often combine with O and N--90% of all compounds are organic

--carbon has 4 valence electrons which allows it to form many bonds to achieve stability. 4 single bonds, a double bonds, etc.

--basically any combination of 4 to meet valence electrons3 forms of carbon

1. Diamond

2. Graphite

3. Fullerenes ( large hollow spheres or cages of carbon) found in meteorites

Saturated Hydrocarbons

Hydrocarbon – organic compound that contains only the elements hydrogen and carbon

Ex: methane

Saturated hydrocarbon – all bonds are single bonds . These use the maximum amount of hydrogen atoms for each carbon atom

Properties of a hydrocarbon are determined by

1.the number of carbon atoms –more carbon atoms, the higher the boiling point

2. the arrangement of the atoms

3 ways to arrange carbon

1. Straight chains (see figure 4 page 264)

2. Branched chains– (compare how butane to isobutane on page265)

--have the same molecular formula, just a different structure isomers –these structural differences can effect some properties of the isomers

--more carbons we add, the more isomers we could have

3. Rings – (see figure 5 on 265)

Note Guide 5-3 day 2

--Unsaturated Hydrocarbons:

-sometimes hydrocarbons can contain multiple bonds (double, triple) = unsaturated hydrocarbons.

-We classify unsaturated hydrocarbons by bond type and arrangement of the carbon atoms

3 Types:

1. Alkenes: have a double bond between the two carbon atoms. (draw ethene diagram pg 266 in notes)

--fruit bearing plants produce ethene.

--names in end -ene2. Alkynes: hydrocarbons that have one or more triple bonds. (draw

ethyne diagram pg. 266 in notes)

--most reactive hydrocarbon--names end in -yne

3. Aromatic: hydrocarbons which contain similar ring structures (draw benzene ring from 266 in notes)

--many of these compounds have strong odor

Most common hydrocarbon in our everyday life? Fossil fuels!

Fossil fuels are mixtures of hydrocarbons formed from plant and animal remains.

3 types of fossil fuels:

1. Coal: mostly aromatic hydrocarbons. High ratio of carbon to hydrogen, causing more soot when burned.

2. Natural Gas: made from marine remains. Main ingredient is methane—same stuff produced by cows as they digest grass. Also contains ethane.

3. Petroleum: crude oil, texas tea! Made from marine organisms

--Complex hydrocarbons(long-branched alkanes and alkynes)

--useful only if separated into simpler mixtures: gas & heating oil.

--To use fossil fuels, we must combust (burn) them. The combustion of fossil fuel produces 2 primary products:

1. Carbon dioxide: if too much fossil fuel is burned, an increase in the amount of CO2 may increase temperature, amounts of rain and sea levels around the world.

--too much burning also causes the acidity of rain to increase.

--rain has some acidity, with a pH of about 5.6.

--the burning increases sulfur dioxide and nitrogen oxides and when dissolved in water, produces sulfuric acid and nitric acid!

--causes structural damage on metals and concrete

Note Guide 5-4 Organic Acids and Bases

--Hydrogen atoms can be replaced in a reaction by an atom or by a group of atoms = substituted hyrdrocarbon

--the atom or group of atoms that does the substitution is called the functional group.

--functional group determines the properties of the compound

--Organic Acids:

--citric acid is an example of an organic acid (sour taste in lemons)--the functional group is a carboxyl group (-COO)

--Organic Bases:

--amime is an example of an organic base (smell of rotten fish)

--functional group is amino group )-NH2

Monomers and Polymers, Oh MY!

--sometimes molecules can be built up from smaller units which are linked together:

-Polymer: large molecule that forms when many smaller molecules are linked together by COVALENT BONDS!

--the smaller units are called monomers

--sometimes polymers are made up of just one monomer or they can be made up of more than one monomer

--can be natural (cotton and wool) or synthetic (man made)

--synthetic examples: nylon, rubber, polythylene (plastics)