Grade 9 Academic Science
Lab Report – Format Examplar Level 4
Hypothesis: Simple signs can indicate a chemical change
Materials:
•
Eye protection
•
Test tube
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Single-holed rubber bung (rubber stopper) and delivery tube to fit conical flask.
•
500 mL beaker
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2-100 mL measuring cylinders
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Clamp stand, boss and clamp
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Stop-clock or watch
•
Graph paper
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One 3 cm magnesium ribbon
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Dilute HCl, 1 mol dm-3
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200 mL of water
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Wooden splint
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Bunsen burner and sparker / lighter / matches
Figure 1. Setup for Experiment
Methods
1. Put on eye goggles
2. Construct experiment equipment as shown in Figure 1. Do NOT insert the bung into the test
tube.
3. Measure 10 mL of HCl and pour it into the test tube or flask
4. Measure 100 mL of water and keep it in the measuring cylinder
5. Measure 100 mL of water and pour it into the beaker
6. Place the cylinder with the water upside down the in the trough (see Figure 1)
7. Measure the volume of water in the graduated cylinder
8. When you are ready, add the strip of magnesium ribbon to the flask, and put the bung back
into the flask as quickly as you can.
9. Observe the volume of water in the cylinder.
10. Conduct a gas test. Light one end of the splint with a match, lighter or the bunsen burner.
11. Remove the cylinder from the trough KEEPING IT UPSIDE DOWN
12. Insert the splint into the cylinder.
13. Record observations and results
Results
If you add Mg metal to hydrochloric acid, the Mg will dissolve to bond with Cl2 and the reaction
will form bubbles of hydrogen gas. This is a single displacement reaction (i.e., Mg replaces H2). A
chemical change occurred because (1) gas was produced, (2) heat was given off (i.e., the test
tube became hot to touch) and (3) bubbling was observed in the reaction test tube. According to
Stride (2011), these are indicators of a chemical reaction.
Discussion
There are many signs of a chemical change. According to "How Stuff Works" (2011), three signs
are (1) energy production, (2) gas production and (3) explosive reaction. In this experiment, heat
was produced as the test tube with the Mg-HCl mixture. This reaction is called an exothermic
reaction. An exothermic reaction is a chemical reaction that releases energy in the form of light
or heat (Wikipedia (a), 2011).
Bubbles were observed in the water column of the graduated cylinder. Since hydrogen gas is
colourless and odourless (Wikipedia (b), 2011), the only way to "see" the gas is via bubbles. As
the number of bubbles increased, the water in the graduated cylinder was pushed downward.
Hydrogen gas is less dense than water (Wikipedia (b), 2011). Thus, the gas rises to the top of
the cylinder. As more gas collects (i.e., the volume of hydrogen gas increases), it fills the space
and pushes the water downward. Initially, the water dropped quickly, but as the experiment
continued, less gas was produced and the water dropped less quickly.
When the burning splint was inserted into the graduated cylinder containing the collected gas,
there was an explosion (i.e., popping sound). This demonstrated a gas had been collected,
although the gas was colourless and odourless. A splint test proves the presence of gas (Stride,
2011).
Conclusion: In conclusion, it is possible to prove that hydrogen gas was produced in a chemical
reaction by performing a number of simple tests. (Refer to the hypothesis)
Literature Cited
 How Stuff Works. 2011. Chemical Changes. Online http://www.ric.edu/faculty/ptiskus/chemical/

Stride, Fred. 2011. Personal communication.

Wikipedia (a). 2011. Exothermic Reaction. Online http://www.google.ca/#hl=en&rlz=1W1ADSA_en&q=exothermic+reaction&oq=exothermic
&aq=1&aqi=g10&aql=f&gs_sm=c&gs_upl=3703l5563l0l10l9l0l2l2l0l281l1220l1.3.3l7&bav
=on.2,or.r_gc.r_pw.&fp=456a37645109cd6b&biw=996&bih=573

Wikipedia (b). 2011. Hydrogen. Online - http://en.wikipedia.org/wiki/Hydrogen