SCH4C1
MATTER
By definition, matter is anything that has mass and volume (e.g. a rock, water or
the atmosphere). Matter is commonly found in 3 states: solid, liquid or gas.
The Changes of State of Matter
GAS
SOLID
LIQUID
Changes of state are an example of physical changes. A physical change is one
that alters the physical appearance of matter but does not affect the composition.
For example, water as ice, liquid water of gaseous water vapour has the constant
composition H2O (2 atoms of hydrogen + 1 atom of oxygen).
ice
H2O (s)
water
H2O (l)
water vapour
H2O (g)
In contrast, a chemical change is a change in a substance which converts it into
different form(s) of matter, each with a different composition and unique
properties.
water
H2O (l)
hydrogen gas + oxygen gas
H2 (g)
+
O2 (g)
The Classification of Matter
Matter
Heterogeneous
Matter
Homogeneous
Matter
Pure Substances
Elements
Solutions
Compounds
Matter:
- anything that has mass and takes up space.
Mixture:
- a combination of 2 or more pure substances.
Heterogeneous Matter:
- consists of 2 or more pure substances
- also called mechanical mixtures (ordinary, colloid, suspension)
- the mixture has 2 or more phases or parts
Homogeneous Matter:
- has only one phase with the same properties throughout
- may be a pure substance or a solution (a uniform mixture)
Solutions:
- homogeneous mixtures consisting of 2 or more substances
- can consist of liquids, solids or gases
Elements:
- elements are pure substances that cannot be broken down into simpler
substances by chemical reactions.
Compounds: - compounds are pure substances consisting of 2 or more elements bonded
together. Compounds can be decomposed into simpler substances by chemical
reactions.
Elements and Compounds have distinct and unique properties that can be used to identify
them (e.g. boiling point, melting point, density, colour, odour, hardness etc.).
Questions:
1. Calcium chloride is used on roads to melt ice. State whether each of these properties is
physical (P) or chemical (C).
a) Calcium chloride is white. ______
b) Calcium chloride has a melting point of 782oC. ______
c) Calcium chloride has a density of 2150 kg/m2.
______
d) Calcium chloride forms chlorine gas when mixed with sulfuric acid. ______
e) When heated in air, calcium chloride produces calcium oxide and chlorine gas. ______
f) Calcium chloride is soluble (dissolves) in water. ______
2. Classify each of the following changes as physical (P) or chemical (C).
a) Water boils in a kettle.
_____
b) Propane burns in a barbeque.
_____
c) Sugar dissolves in hot tea.
_____
d) Butter melts on hot toast.
_____
e) Copper wire is bent into a coil.
_____
f) A candle burns.
_____
g) An sliced apple turns brown.
_____
3. Name the physical property described by each of these statements.
a) Aluminum metal can be hammered into thin sheets. ____________________________
b) Copper wire is used for electrical circuits. __________________________
c) The mass of one milliliter of water is one gram. __________________________
d) Diamond can scratch glass. ______________________
e) Iron (III) oxide is a red solid. ________________ and ____________________
4. Classify the following substances as a pure substance (PS), solutions (S) or mechanical
mixture (MM). For the pure substances, indicate if it is an element (E) or compound (C).
a) clear tea ___________
b) caffeine (C8H10N4O2) ___________
c) sodium _________
d) salt and pepper __________
e) rubbing alcohol (70% isopropyl alcohol) ________
f) air ________
g) tap water __________
h) oxygen _________
i) muddy water ________
5. Write down as many properties of water that you can think of. For each, classify it as a
physical or chemical property.