SNC2D – Chemistry: Chemical Reactions
Chemistry Review: Classifying Matter, Physical/Chemical Properties
and Changes
1. Complete the following diagram for the classification of matter, using the following terms:
matter, pure substances, mixtures, homogeneous mixtures, elements, heterogeneous
mixtures, compounds. Write 1 example of each.
Matter
Pure substances
(1 kind of particle)
Elements
(1 kind of atom,
in periodic table)
Compounds
(CO2, H2O, in
fixed ratios)
Mixtures
Homogeneous
mixtures
(e.g. coke, tap
water)
Heterogeneous
mixtures
(tossed salad,
pizza)
2. What is the difference between a chemical property and a physical property?
Physical: characteristic or description of a substance. E.g. colour, texture,
smell, melting point, viscosity
Chemical: characteristic behaviour that occurs when the substance
changes into something new. E.g. flammable, corrosive, reacts to an acid
3. Classify each of the following observations as an example of either a chemical or a physical
property:
Chemical or Physical?
(a) Liquid nitrogen boils at -196 C.
Physical
(b) Propane, leaking from a damaged tank, ignites easily.
Chemical
(c) Silver jewellery tarnishes (darkens) in air.
Chemical
(d) Spilled oil generally floats on the surface of the water.
Physical
SNC2D – Chemistry: Chemical Reactions
4. What is the difference between a chemical and a physical change?
Physical: not a change in the chemical properties, can be change of
state/phase, dissolving, usually reversible;
Chemical: new substance formed; new chemical properties;
5. Identify 5 pieces of evidence that could indicate a chemical change has taken place.





Colour change
Light or heat produced
Bubbling, gas produced
Usually difficult to reverse
A solid precipitate is formed from 2 liquids
6. Classify each of the following situations as a chemical or a physical change, and justify your
answer:
Chemical or Physical?
(a) Air is often blended (dissolved) into ice cream to give it a
lighter texture.
Physical
(b) When popping corn is heated, water inside the kernels
becomes a gas and expands. When popping corn is heated,
water inside the kernels becomes a gas and expands. This
creates enough pressure to explode the kernel.
Physical
(c) A loud pop is heard when a lit match is placed at the mouth
of a test tube containing hydrogen gas.
Chemical
(d) Cola is used by auto mechanics to clean the crusty solids
around battery terminals. Bubbles of carbon dioxide gas are
observed when cola contacts the solid.
Chemical
SNC2D – Chemistry: Chemical Reactions
Physical/Chemical Properties and Changes Homework
1. For the following pairs of properties, choose one of these four answers and place its number
in the space provided:
1.
2.
3.
4.
a)
b)
c)
d)
e)
f)
g)
Both are PHYSICAL properties
Both are CHEMICAL properties
The first is a PHYSICAL property, the second is a CHEMICAL property.
The first is a CHEMICAL property, the second is a PHYSICAL property
Green and powdery
Combustible and oily
Insoluble, and turns black when heated strongly
Bubbles with hydrochloric acid, and burns
Fusible and corrodes
Produces a choking gas with nitric acid, soluble in
turpentine
Shiny and less dense than water
1 (P & P)
4 (C & P)
3 (P & C)
2 (C & C)
3 (P &C)
4 (C & P)
1 (P & P)
2. The solvents in house paint allow the paint to flow smoothly onto a surface. Once the paint is
exposed to the air, these solvents evaporate and the paint dries. What chemical and physical
properties should these solvents have? What other characteristics should the ideal solvents
have?
Mixes easily, non-viscous, non-aromatic (non-smelly), evaporate quickly
3. Drain cleaners often produce a great deal of heat as they unclog drains. Is the action of the
drain cleaners a physical or chemical change? Explain your answer.
Chemical change – heat released
4. Describe 2 physical properties and one chemical property necessary for the materials used
for dental braces.
Non-toxic, doesn’t react to any food, non-corrosive, rigid, pliable, adhesive