Science 24 Chapter 1 Notes.notebook February 19, 2015 1.3 Chemistry at Home Many cleaning products in your home start chemical changes to break down dirt ex. Sodium hydroxide: a base found in drain and oven cleaners. It is highly corrosive and can break down proteins in skin, hair, and animal fat, to clean clogged drains. Hydrogen peroxide: when poured on a cut, turns into water and oxygen (a chemical change), causing foaming. The foaming helps remove small particles from the broken skin and kills bacteria. Almost all products have safety warnings on the labels: The Hazardous Household Product Symbols HHPS matching activity
Transcript
Science 24 Chapter 1 Notes.notebook February 19, 2015
1.3 Chemistry at Home
Many cleaning products in your home start chemical changes to break down dirt
ex. Sodium hydroxide: a base found in drain and oven cleaners. It is highly corrosive and can break down proteins in skin, hair, and animal fat, to clean clogged drains.
Hydrogen peroxide: when poured on a cut, turns into water and oxygen (a chemical change), causing foaming. The foaming helps remove small particles from the broken skin and kills bacteria.
Almost all products have safety warnings on the labels: The Hazardous Household Product Symbols
HHPS matching activity
Science 24 Chapter 1 Notes.notebook February 19, 2015
Hazardous Household Product Symbols
Science 24 Chapter 1 Notes.notebook February 19, 2015
Chemistry and Cooking
‐ It is important to know how ingredients will react when baking and cooking.
‐ Ex. Yeast is a single celled organism that converts food like sugar into carbon dioxide and alcohol.
How does this help make good bread?
‐ Ex. Vinegar and baking soda also make carbon dioxide gas. This can be used to make sponge toffee.
Science 24 Chapter 1 Notes.notebook February 19, 2015
Chemical and Physical Properties and Changes
‐ A physical change is a change in a material’s appearance but NOT its composition.
‐ Ex.
o Cutting a piece of paper
o Boiling water
o Mixing paint
o Breaking glass
‐ A chemical change is a change that results when two or more substances react to create a different substance or substances. The new substance (s) have completely different properties from the original ones.
‐ Ex. o Burning a piece of papero Apple rotting
o Mixing baking soda and vinegar
o Digestion of foodo Metal rusting
Science 24 Chapter 1 Notes.notebook February 19, 2015
1.4 Chemistry at WorkBefore: chefs, blacksmiths, and welders all needed "chemistry" in order to function.
Ex. Welders: steel needs high temperature in order tomelt. A chemical change between oxygen and acetylene gas provides this heat.
Now: chemistry is used in every workplace
1) Automotive Repair Shop: paints (rusting), fillers, and cleaners (chemical reaction)2) Hair Salon: colorants, curling solutions, and shampoos3) Office: inks, toner cartridges, fire retardants4) Construction Site: explosives, wood preservatives, solvents
Science 24 Chapter 1 Notes.notebook February 19, 2015
Cosmetic Chemistry
People used to use soap to wash hair. Soap is a base, which can break down proteins in hair and leave scum due to reactions with calcium in water. Hair is dull and rough
How can we get rid of the scum?
Add and acid to neutralize the base! Rinse with lemon juice or vinegar.
Now, we use shampoo: a mild synthetic detergent.
Some shampoos use plastics to texturize hair!
Many cosmetics are tested on animals.
Today, many groups oppose this testing. Knowledge of chemical reactions can help control chemical reactions, eliminating their need for animal testing.
Look for bottles with these labels:
Science 24 Chapter 1 Notes.notebook February 19, 2015
The Key to Chemical Safety
WHMIS Workplace Hazardous Materials Information System provides information on how to store, handle, and dispose of materials at workMSDS Material Safety Data Sheets detailed information that will not fit on product label
Science 24 Chapter 1 Notes.notebook February 19, 2015
Naming and Counting Atoms
1) Find the chemical symbol of each element using the Periodic Table. Write down the names of the elements you have.
ex 1)
ex2)
2) Count the number of atoms for each element. a) coefficients mean you have that many
moleculesb) subscripts indicate the number of atoms of an
