STAGE 1 ChemistryIntroduction & Revision
Introductory Activity:
Let’s Start with Copper
Chemistry is the study of materials of which everything is made – rocks, metals, air, flowers and
trees, animals and humans.
Chemistry is the study of nature of these materials – their softness or hardness, whether or not
they burn, whether or not they are poisonous. Chemists try to explain why these materials behave
as they do.
In chemistry we use skills such as observing, measuring, recording, classifying, inferring, predicting,
hypothesising and developing generalisations. During this series of investigations, you will be
expected to use these skills to find answers that are asked about the changes that occur.
SIS Science Inquiry Skills
Observations & Hypothesis
Evidence of Chemical Reactions
Materials can undergo chemical change. For example, trees growing, wood burning, digestion of
food and manufature of plastics all involve chemical reactions. When chemical changes take place
we may observe one or more of the following:

A gas is given off.
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A colour change takes place.
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A solid is precipitated.
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The temperature changes.
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A new odour appears.
These are the kinds of evidence used to indicate that a chemical reaction is taking place. After the
investigations you may be able to suggest other evidence that indicates a chemical change is
occurring.
Procedure & Observations
You will start with small pieces of copper metal. Our interest is in finding out if chemical changes
are taking place. You should think about where the copper is during the following series of
investigations.
Stage 1 Reaction between copper, Cu, and a solution of nitric acid, HNO3, in water.

You are given a piece of copper weighing approximately 1.5 g. Weigh the copper and record
its mass.
Mass of copper: ____________________

Cut up the copper and place the copper in a 250mL beaker.

Describe the copper. Use descriptive terms such as solid, liquid, gas, transparent, opaque,
shiny, dull etc.
Description of copper:
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Describe the nitric acid solution provided.
Description of nitric acid:
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Hypothesise what you think will happen when the two are mixed.
Hypothesis:
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SIS Science Inquiry Skills
Safety
 With care, THE ACID IS CONCENTRATED AND
CORROSIVE, measure out 15 mL of the nitric acid
solution in a measuring cylinder.

In the FUMEHOOD, pour the acid solution into the beaker
containing the copper. THE GAS THAT IS FORMED IS POISONOUS.


Place a watch glass on top of the beaker.
As the reaction proceeds, record your observations.
Observations:
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
Keep the product in the beaker for Stage 2 of the investigation.
Do you think that a chemical reaction occurred? Provide evidence to support your answer.
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The copper metal is no longer there. Where is it? Later stages of the experiment may help you
answer this question.
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Stage 2 The addition of a solution of sodium hydroxide, NaOH, in water.
Describe the sodium hydroxide solution provided.
Description of sodium hydroxide:
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Hypothesise what will happen when the sodium hydroxide is added.
Hypothesis:
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
To the solution in the beaker slowly add 40mL of the sodium hydroxide solution while gently
stirring with a glass stirring rod.

Record you observations.
Observations:
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Has a chemical reaction occurred? How do you know? Where do you think the copper is now?
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SU Science Understanding
Identify how components of a mixture can be separated by methods including filtration, distillation
and evaporation.
Separating Mixtures
Decanting/Decantation
Decanting is a method used to separate two liquid layers or a liquid
layer and a suspended layer solid layer using gravity. The layers are
allowed to settle and then separated. One layer is carefully poured off
of the other layer or passed through a separating funnel with a tap.
Filtration
Filtration is a method used to physically separate insoluble solid
from a solvent (such as water). The mixture is passed through
porous filter paper, which is folded and sits inside a funnel.
The liquid passing through the filter paper is referred to as the
filtrate. The solid remains on the filter paper and can be dried.
(Chemistry SACE 1 AC Essentials Workbook, 2016)
Evaporation
Evaporation is another method of separating a soluble solute or
solid from a solvent in solution. The solution is placed in an
evaporating dish and heated (often over a steam bath). The
solvent slowly evaporates off leaving the solid solute.
(Chemistry SACE 1 AC Essentials Workbook, 2016)
Decanting will be used in Stage 3.
Suggest why filtration will be used in Stage 6, in preference to evaporation for this investigation.
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Stage 3 Heating

Add 100 mL of distilled water to the
beaker.

Gently heat the beaker and its contents
whilst stirring constantly.

Continue heating and stirring until the
solution boils and no change can be
seen.

Record all observations.
Observations
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Has a chemical reaction occurred? State you evidence?
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
Lift the stirring rod out of the solution.

Use a wash bottle to wash any particles on the stirring rod into the beaker.

Allow the beaker to cool for 5 minutes.

Without losing any solid, pour off as much of the clear liquid as possible.

Wash the solid in the beaker by adding 100 mL of distilled water while stirring.

Wash any particles from the stirring rod into the beaker.

Allow the solid to settle and pour of the clear liquid.

Repeat the washing procedure, allow the solid to settle and pour off the clear liquid.

Keep the product for the next stage of the investigation.
Stage 4 Addition of a solution of sulfuric acid, H2SO4, in water

Describe the sulfuric acid provided.
Description of sulfuric acid.
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
Hypothesise what will happen when the sulfuric acid is added.
Hypothesis:
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
Carefully add 50 mL of the acid solution to the beaker and stir until no further change takes
place.

Record your observations.
Observations
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Has a chemical reaction occurred? Give reasons for your answer. Where is the copper now? Do you
think the colour of the product is significant? Why?
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
Keep the product for the next stage of the investigation.
Stage 5 The addition of zinc metal, Zn.

Describe the zinc metal.
Description of the zinc:
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
Hypothesise what will happen when zinc is added to the beaker.
Hypothesis:
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
Add approximately 5 g of powdered zinc metal to the product in the beaker. Place a watch
glass on top of the beaker.

Swirl the beaker occasionally.

Carefully observe any changes that occur and record your observations.
Observations:
________________________________________________________________________________
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Has a chemical change occurred? State your evidence. Where is the copper now?
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
Allow the reaction to proceed until all the zinc has disappeared and any bubbling has stopped.

Keep the product for the next stage of the investigation.
Stage 6 Recovery

Pour off the clear liquid from the solid in the beaker.

Wash the product with approximately 50 mL of water.

Stir, allow to settle and pour off the clear liquid again.

Weigh a filter paper.
Mass of filter paper: ___________________

Filter the solid from the beaker.

Allow the solid on the filter paper to dry overnight.

Describe the product.
Description of the product:
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Has a chemical change occurred? State your evidence.
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
Weigh the filter paper with the product.
Total mass: _______________________

Calculate the mass of the dry product.
Mass of dry product: ______________________
Discussion point: Compare the mass of the final product with the mass of the copper you began
with in Stage 1. What do you think the product is? How would you test your conclusion?