Instructions for the stations. Cut out each cell from the table and paste them in your
notebook, one per page.
1) (i) Temperature change
You are going to experiment with different ratios of reactants
 Measure 5 mL of 0.5M HCl (hydrochloric acid) in a measuring cylinder and 15 ml of
0.5M NaOH (sodium hydroxide) in another measuring cylinder.
 Measure the temperature of the two solutions (be sure to rinse your thermometer
between solutions)
 Pour both solutions into a 100 ml beaker and measure the temperature of the
solutions (record the highest temperature).
 Add 2 drops of universal indicator to the beaker and record a qualitative observation
of the color.
 Repeat the experiment two more times, once with 10 ml of each solution and another
time with 15 ml of HCl and 5 ml of NaOH.
1. Make an x,y scatter graph of your results.
2. What is the most effective ratio for the reaction? Explain, using your quantitative and
qualitative data.
1) (ii). More temperature change
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In a 250 ml beaker place 25 ml of vinegar and measure the temperature.
Add two large scoops of baking soda (NaHCO3) to the beaker and continue to
measure the temperature every 30 sec until it stops changing. Put your results into a
table. Record any other qualitative observations you have.
1. Make an x,y scatter graph.
2. How is the quantitative data different from the first series of experiments?
3. Why does the temperature stop changing? What qualitative observations justify this
conclusion?
2) Production of a gas
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Add 25 ml of 0.5M HCl to a 250 ml beaker.
Measure the mass of the 250 ml beaker with the HCl and a glass stir rod on a 2
decimal place balance.
Measure out approximately 0.5g of baking soda (NaHCO3). Record the mass of
baking soda that you use.
Slowly add baking soda (NaHCO3) to the 250 ml beaker Gently stir the mixture until
you observe that the reaction has finished (gone to completion).
Record the mass of the beaker + HCl + stir rod + soda again.
1. Make a bar graph to illustrate the change. Think about how you can scale the y-axis
to make the change visible on the graph.
2. Is the mass of the same before and after?
3. Where did the mass go? What qualitative observation supports this conclusion?
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Repeat the experiment two more times, once with approximately 1 g of soda, and
once with approximately 2 g of soda.
1. Make another two bar graphs to show the difference before and after.
2. How do these results differ from the first trial? Can you explain your data in terms of
particles?
3) (i) Combustion/Light
Candles give off light (and heat) because a chemical reaction is happening. This type
of chemical reaction is called combustion and involves the rapid reaction of a fuel with
oxygen to make carbon dioxide and water.
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Measure and record the mass and height (base to top of the wick) of a candle then
light it. Let this candle burn in a safe place while you are conducting the other
experiments.
Measure and record the mass and height of the candle again.
Measure and record the mass of a piece of string that is the length by which the
candle got shorter.
1. How did the mass change? Where did it go?
2. What is the main fuel for the candle? How do your results show this?
3) (ii). What form of wax burns (combusts)?
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Light another candle.
One group member blow out the candle.
While the candle is still “smoking” slowly lower a lit match above the candle in the
“smoke”. Record your qualitative observation. (don’t forget to blow out the candle)
Briefly hold a lit match to the side of the candle. Record your qualitative observation
1. What burns, solid wax, liquid wax or wax vapour? How do your qualitative
observations show this?
3) iii. Limiting combustion
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Light the candle again. This time place a 250 ml beaker over the candle.
Using a stop clock, measure how long it takes for the candle to go out.
Repeat with a 500 ml beaker.
Make a bar graph that compares the two times.
1. How are the times different? Does it take twice as long for the candle to burn out
under the 500 ml beaker? If no, why? Explain your results using what you know about
chemical reactions and particles.
4) Formation of a precipitate i) Blowing in lime water
A precipitate (ppt) is solid that forms in a solution.
 Place some lime water (Ca(OH)2(aq)) in a small conical flask.
 Record your qualitative observation(s) of the lime water.
 Using a straw, blow bubbles into the lime water for 1 min.
 Record your observation(s) of the lime water after you’ve blown in it.
Our breath contains carbon dioxide (CO2). Carbon dioxide reacts with Ca(OH)2 to form
CaCO3 and water.
1. Write the chemical equation for the reaction.
2. Circle the compound that is not soluble in water. How do your observations indicate
that a chemical reaction has taken place?
4) ii. Precipitate as indication of reaction
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Place 2cm depth of NaCl, NaNO3, or Na2SO4 into three test tubes (one solution per
test tube)
Drop 1 drop of BaCl2 into each test tube and record your observations.
1. With which compound(s) did the BaCl2 react? How do your qualitative observations
support this?
2. Can you suggest a chemical equation for this reaction?
4) iii. Precipitate as indication of ratio of reactants.
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Using 5 test tubes you will make test 5 different ratios of reactant solutions.
In the first test tube place 1 drop of copper sulphate, in the second place 2 drops, 3rd
3 etc
In the first test tube place 4 drops of NaOH, in the second 3 drops etc
Mix the solutions by gently swirling the test tubes. Then allow the solution to settle.
Record your qualitative observations.
1. Which ration produced the most product? How do your qualitative observations
support this conclusion?
2. Can you suggest a chemical equation for the reaction (hint: one product is
Cu(OH)2(s))?