Water Chemistry

Essential Questions What are some unique qualities of Water?

Polarity Water has a partial negative charge near the oxygen atom due the unequally shared pairs of electrons, and partial positive charges near the hydrogen atoms. Hydrogen bonds form between the partial positive H and the partial negative O, linking water molecules together The ability of ions and other molecules to dissolve in water is due to polarity. Introduce Polarity Demo from “Demo a Day volume 2” Page 164 Use charged PVC pipe to deflect a stream of water.

Hydrogen Bonds Many of water’s unique properties are due to the hydrogen bonds Ice floats Cohesion: Water is attracted to water Adhesion: Water is attracted to other substances High surface tension Water Delivery from “A Demo a Day” volume 1 page 121 Float a needle to make a compass. Capillary Action/ color chromatography? Adhesion/Cohesion can be demonstrated using two microscope slides and a drop of water. Do as minilab.

Hydrogen Bonds High Specific Heat - The specific heat of water is the amount of heat needed to raise its temperature a certain amount. One of water's most significant properties is that it takes a lot of heat to it to make it get hot. The high specific heat capacity of water has a great deal to do with regulating extremes in the environment. Fireproof Balloon Demo

pH pH is a measure of how acidic/basic water is. The range goes from 0 - 14, with 7 being neutral. pHs of less than 7 indicate acidity pH of greater than 7 indicates a base pH is really a measure of the relative amount of free hydrogen and hydroxide ions in the water

Carbon Chemistry

Essential Questions What are the three forms of Carbon? What factors determine the properties of a hydrocarbon? What are the three types of unsaturated hydrocarbons?

Branches of Chemistry Inorganic – Organic – the chemistry of compounds that do not contain hydrocarbons Organic – The chemistry of carbon compounds (other than simple salts such as carbonates, oxides, and carbides). Originally thought that they could only be made from living things.

Forms of Carbon Diamond is a network solid All the same type of atom linked by covalent bonds Diamond is the hardest mineral because each carbon atom is bonded to 4 other carbon atoms in a 3-D structure. Graphite – atoms are arranged in layers. They are bonded to atoms in that layer, but not in other layers. Fullerenes – large hollow spheres or cages of carbon.

Saturated Hydrocarbons All bonds are single bonds Contain the maximum number of Hydrogen Known as Alkanes Like Methane, Ethane, Propane, Butane CH4, C2H6, C3H8, Have students build several with new model sets

Forms of Hydrocarbons Straight Branched Rings Modify straight to be branched or rings

Unsaturated Hydrocarbons A hydrocarbon that contains one or more double or triple bonds. 3 types – Alkenes, alkynes, and aromatic hydrocarbons. Ethane Ethene ethyne AKA Acetylene

Substituted Hydrocarbons A hydrocarbon in which one or more hydrogen atoms have been replaced by another atom or group of atoms. That atom or group of atoms is known as a functional group. Alcohols – The functional group is a hydroxyl group. - OH.

Substituted Hydrocarbons Organic Acids and Bases The functional group in organic acids is a carboxyl group – COOH.

Esters Esters form when organic acids react with alcohols. They account for the flavors of many foods and the pleasant odor of many flowers. Used in many processed foods to produce flavors such as strawberry, banana and grape. Roses and other flowers produce esters to attract insects for pollination.

Polymers What are polymers? What are some examples of synthetic polymers? What are four types of polymers that organisms can produce?

Polymers A polymer is a large molecule that forms when many smaller molecules are linked together.

Synthetic Polymers Rubber Nylon Plastics Adhesives Paints Polyethylene Polyester Polycarbonate Adhesives Paints

Natural Polymers Four types of Polymers produced in plant and animal cells are: Starches Cellulose Nucleic acids Proteins

Sugar and other Monomers Glucose is the product of photosynthesis, and the building blocks for starch and cellulose. Proteins are made from Amino Acids. The instructions for making those proteins comes from your DNA

Starch Carbohydrates – sugars and starches There are simple sugars like glucose and fructose. They can combine to make more complex sugars like sucrose and lactose. 100’s of glucose monomers join together to form starches like those found in grains, potatoes, etc. Bring in saltine crackers and have each student place a piece of the cracker on their tongue and soak it in saliva until it tastes sweet. Explain that Amylase starts to break down the Amylose into simple sugars that taste sweet.

Cellulose The main component of cotton and wood. The most abundant of all organic compounds found in nature. Contain 3000 or more glucose monomers.

Nucleic Acids DNA and RNA Large Nitrogen containing polymers http://youtu.be/V9BZ3zx 8b8I

Proteins Chains of Amino Acids Enzymes