Unit A: Matter and Chemical Change Science 24 Mrs. Sample

Chapter 1 Useful Chemistry

In this chapter you will learn:  how new materials have changed everyday life over the past 100 years  about some chemical changes involved in cooking, cleaning and gardening  about the role of chemicals in the workplace  how to interpret safety information at work and home

Chemistry on the Farm  Advances in chemistry and technology have had a significant impact on the farming industry, including:  Equipment  Pest control  Fertilizers

Farm Equipment 100 years ago:  Human labour  Teams of horses Now:  Tractors  Automatic feeders  Barn cleaners

Pest Control 100 years ago:  Pulling weeds  Hand-picking insects off of plants Now:  Synthetic pesticides  Herbicides kill weeds  insecticides kill insects

Fertilizer 100 years ago:  Manure  Worms  Compost Now:  Synthetic/chemical fertilizers

Cleaning 100 years ago:  Homemade soap  Materials included ashes from the cooking stove and animal fats.  Beef fat was used the most often! Now:  Manufacturers have replaced some or all of the animal fat with plant oils.  For example, coconut oil may be used to make a soap that has a nice scent and cleans very well.

How Does Soap Work? Many cleaners include strong bases. Bases produce soap when they react with the fatty acids in grease. Soap consists of a two-ended molecule. One end of the molecule dissolves in grease and the other dissolves in water. This reaction enables us to wash away grease.

Chemistry and Synthetics 100 years ago:  All clothing was made from natural fibres such as cotton, flax, wood and silk. Now:  We still use the natural form of cloth.  Many other type of fibres have been developed in the chemistry lab

Why Synthetics?  Synthetic materials are useful because they can be designed to fit a purpose or need.  Nylon  Gore-Tex  Kevlar  Neoprene

Check Your Understanding  How have chemicals made modern farming easier than it was 100 years ago?  How has the process of making soap changed over the past 100 years?  Name two synthetic and two natural fibres. Describe at least two advantages of synthetic fibres.

1.2 Plastics, Polymers and Alloys Science 24

Polymers  Polymers are materials consisting of long chains of molecules.  Many polymers occur in nature. For example, the silk in spider webs and the sap from rubber trees are two natural polymers.  Synthetic polymers are human-made materials, often spun into thread to make fabrics or moulded to form plastics.

Synthetic Polymers PolymerSignificant PropertiesUses NeopreneRubbery, porous, insulating, does not react readily with other chemicals Shoe soles, hoses, wet suits PolyethyleneCan be easily formed into lightweight containers Milk jugs PolystyreneDoes not absorb water, poor conductor Styrofoam cups, insulation PolyurethaneFlexible, fibrous, does not absorb water Upholstery, clothing

Lab: Make Your Own Polymer

Alloys  Many of the products you use today – from cars to jewellery – are made from alloys.  Definition:  An alloy is two or more metals mixed together, but still looks like one metal

Properties of Alloys  Alloys have properties of the original metals that make up the alloy.  What kind of properties do metals have?

Examples  Stainless steel is an alloy of iron and chromium  It has the strength and durability of iron, and chromium’s resistance to rusting  Brass is an alloy of copper and zinc  Solder is an alloys of lead and tin

Homework  Textbook page 11 # 1-3

1.3 Chemistry at Home

Chemicals in the Cupboard  If you did a quick survey of the cupboards in your kitchen, bathroom and laundry room, you would probably find a wide variety of chemicals.  In your notes, write down 5 chemicals you would find in your house right now.

Chemicals at Home  Many hazardous chemicals are found at home. Some of these substances are stored in a cupboard to keep them away from young children. Others are kept in special containers that prevent accidental poisoning.  Almost all of these products have safety warnings on their labels.  Hazardous Household Product Symbols (HHPS) are designed to be easy to understand. Let’s see what you already know!

Common Household Chemicals ChemicalWhere FoundHow it Cleans Muriatic acid (hydrochloric acid) Steam-iron cleaner Reacts with lime (scaly buildup) to form a soluble product AcetoneNail polish remover Dissolves nail polish so it can be wiped away Methanol (wood alcohol) Paint solventDissolves the paint

Chemistry in the Kitchen  Controlled chemical reactions are fundamental to cooking and baking.  For example, yeast is used to make bread rise.  Yeast is a single-celled organism that needs food, warmth and moisture to thrive. It converts its food (sugar and starch) into carbon dioxide and alcohol. Carbon dioxide bubbles make baked goods rise.  A mixture of baking soda and vinegar has a similar effect. Sponge toffee is a mixture of baking soda, vinegar and sugar.

1.4 Chemistry at Work

What if I Don’t Plan to be a Chemist?  An understanding of chemistry is important in every workplace, whether you work in a chemistry lab, a restaurant, a hospital or an office.  Chemicals are EVERYWHERE, and knowing how to work safely with them is crucial to workplace success.

A Few Workplace Applications of Chemistry Welding Shop  Pieces of steel must be heated to a very high temperature to melt them in order to weld them together.  A chemical change involving acetylene gas and oxygen produces enough heat to melt steel. Automotive Repair Shop  Paints, fillers, and cleaners all involve chemical reactions.  Special car paint protects metal cars from rusting.  Waxes and polishes protect that paint.  When the paint gets faded by the Sun, special waxes may remove tiny amounts of paint to restore the shiny appearance

A Few Workplace Applications of Chemistry Hair Salon  Just about everything except the scissors involves a chemical change.  This includes colorants, curling solutions, shampoos, and conditioners. Office  Hazardous chemicals are common in inks, toner cartridges, correction fluid, and the fire retardants in paper, upholstery, and carpets.

A Few Workplace Applications of Chemistry Construction Site  Hazardous chemicals are found in demolition explosives, wood preservatives, paints for finishing, and solvents for cleaning up.  Many solvents used to clean grease stains or wash windows include ammonia. Ammonia works by dissolving grease, wax and window dirt. Where YOU Work

The pH Scale  The pH scale tells us if a substance is an acid or base. It is a measurement based on the concentration of hydrogen or hydroxide in a substance.

Common Acids and Bases  Pure rainwater  pH 5.5  Sea water  pH 8  Distilled water  pH 7  Detergents  pH 10.5  Blood  pH 7.5  Drain cleaner  pH 14  Ant bites  pH 3  Stomach acid  pH 2

Chemicals and Cosmetics  Cosmetics have been around for thousands of years. Some of these cosmetics are harmless, but others are not.  Many cosmetics are tested on animals before being used on people. Researchers study how much the animals are affected before allowing the material to be used on humans.

Chemical Safety  How do you know what precautions to take when handling a substance you have never used before?  How do you know what to do if you spill a substance you have never used before?  All you have to do is read!

The WHMIS Label Seven items are required on a WHMIS supplier label:  Product identifier  Hazard symbols  Risk phrases  Precautionary measures  First aid measures  Supplier identifier  A reference to the MSDS

WHMIS HAZARD SYMBOLS Compressed Gas

WHMIS HAZARD SYMBOLS Flammable

WHMIS HAZARD SYMBOLS Oxidizing Material

WHMIS HAZARD SYMBOLS Corrosive

WHMIS HAZARD SYMBOLS Poisonous

WHMIS HAZARD SYMBOLS Toxic

WHMIS HAZARD SYMBOLS Biohazardous

WHMIS HAZARD SYMBOLS Reactive

Material Safety Data Sheet  The Material Safety Data Sheet (MSDS) contains additional information about a substance.  An MSDS has 9 sections, and contains a total of 54 pieces of information.

Homework  Textbook page 19 #1-2  Chapter 1 Quiz tomorrow! To prepare, do page # 1, 2, 4, 5, 7, 8, 10, 14, 16