1. CHEMICALS AND CHEMICAL CHANGE
Chapter 5.1
BLM 5.1a, 5.1b

2. Chemicals and Chemical Change
CHEMISTRY – is the study of matter, its changes and its properties.
MATTER – is anything that has mass and takes up space. See excerpt from Bill Bryson
ATOM – the smallest particle of matter. see excerpt from Bill Bryson

3. Pure Substances
A pure substance is one in which all the particles that make up the substance are the same.
Ex. Water – clear, colourless and boils and freezes at the same temperatures.
Pure Substances are classified as elements or compounds.

4. Elements
Elements are pure substances that cannot be broken down into simpler substances.
Ex. Oxygen, hydrogen, iron and mercury are elements because each contain only one kind of atom.

5. Compounds
Compounds are pure substances that contain two or more different elements in a fixed proportion.
Ex. Carbon Dioxide – CO2 is a compound where each molecule is composed of one Carbon atom and two Oxygen atoms.
Ex. Water – H20 is composed of 2 Hydrogen atoms and one Oxygen atom.

6. Properties of Matter
Physical Properties are characteristics of a substance.
Ex. Baking Soda – a white, crystalline solid at room temperature that dissolves readily in water to form a solution

7. Chemical Properties
A Chemical Property is a characteristic of a substance when a substance changes to a new substance.
Ex. Baking Soda and vinegar produces carbon dioxide.

9. PHYSICAL CHANGE – a change in a substance which does not produce a new substance.
EXAMPLE: melting ice become water in a liquid state

10. CHEMICAL CHANGE – a change in a substance which produces a new substance.
EXAMPLE: match burning

11. Chemical Changes
The starting materials in chemical changes are called reactants and the new materials produced are called products.
Ex. Iron and Oxygen are reactants and iron(III) oxide is a product.

12. Using page 173, figure 4 make notes on the clues of chemical changes.
Use the following labels and pages 173 – 174 to complete the handout.
Rusting/corrosion difficult to reverse,
water vapor turns cloudy
new color reactants
Pops oxygen
turns pink products,
Precipitate carbon dioxide,
bursts into flames heat or light
Hydrogen oxygen

13. HANDOUT 5.1b
Use the following labels and pages 173 – 174 to complete the handout
Rusting/corrosion difficult to reverse,
water vapor turns cloudy
new color reactants
Pops oxygen (x2)
turns pink products,
Precipitate carbon dioxide,
bursts into flames heat or light
hydrogen

14. O2 CO2 H2O Pops Corrosion or Rusting Reactants Products Oxygen H2
Tough
to reverse
Colour
Change
Energy
Given off
Precipitate
forms H2 O2
CO2
H2O
Bursts into
Flames
Turns
Cloudy
Turns
Pink
Pops

15. QUESTIONS
Page 175
QUESTIONS: #1,2,4,5,6,7

16. SOLUTIONS TO HOMEWORK QUESTIONS
Q1 – classify each of the following as a pure substance or a mixture
A) soapy water
MIXTURE
B) hydrogen gas
PURE SUBSTANCE
C) sodium chloride

17. QUESTION 2 Classify each of the following as an element or a compound.
A) hydrogen
ELEMENT
B) potassium carbonate
COMPOUND
C) water
D) Mg

18. QUESTION 4
Classify each of the following as a physical property or a chemical property.
A) Gasoline is a clear pink solution
PHYSICAL PROPERTY
B) Gasoline burns in air
CHEMICAL PROPERTY
C) Water boils at 1100C.
D) electric current can split water into hydrogen and oxygen gases

19. QUESTION 5
When aluminum metal is added to hydrobromic acid, hydrogen gas and an aluminum bromide solution are formed.
A) What kind of change has occurred?
Chemical, bubbles formed, new substance made

20. QUESTION 5
When aluminum metal is added to hydrobromic acid, hydrogen gas and an aluminum bromide solution are formed
B) Which substances are the reactants and which are the products?
Reactants – Aluminum and Acid
Products – Hydrogen + Aluminum Bromide

21. QUESTION 6
Describe the chemical tests that can be used to identify the following gases.
A) hydrogen
a flaming wooden splint causes a “pop”
B) Oxygen
a glowing wooden splint relights (bursts into flame)

22. QUESTION 6 C) Carbon Dioxide
A burning wooden splint extinguishes, OR when the gas is bubbled through limewater, the limewater changes from a clear, colourless solution to a cloudy white liquid (a precipitate is formed)

23. QUESTION 6
Water Vapour
Changes the colour of cobalt chloride test paper from blue to pink

24. QUESTION 7
When sodium carbonate is added to water, the sodium carbonate dissolves. When hydrochloric acid is added to the solution, the solution fizzes. What kinds of changes have occurred?

25. QUESTION 7 - ANSWER
When sodium carbonate dissolves in water it is a physical change
A chemical change happens when gas is formed after hydrochloric acid is added ( fizz / Bubbles )

26. Homework Physical or Chemical change: Tell me why Value: 15 marks
(1 mark for whether it is chemical or physical)
(2 marks for your reasoning)