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Chemistry Matters for GCE ‘O’ Level (2 Edition): Full Solutions to Textbook Questions
Chapter 2
Chapter 2
Measurement and Experimental Techniques
Test Yourself 2.1 (page 27)
(a)
(b)
(c)
(d)
(e)
Digital stopwatch
Pipette
Burette
Gas syringe
Electronic balance
Test Yourself 2.2 (page 30)
1. Ammonia, chlorine and hydrogen chloride are soluble in water. They will dissolve in the water.
2.
moist
methane
fused
calcium
chloride
The moist gas is dried by passing it through fused calcium chloride. Since methane is less dense than
air, it has to be collected by upward delivery.
Get it Right (page 31)
(a)
(b)
(c)
(d)
True.
3
False. The volume of liquid in the burette is 13.60 cm .
False. Only gases that are insoluble or slightly soluble in water can be collected over water.
False. Quicklime (calcium oxide) is used to dry ammonia gas.
Let’s Review (pages 31–32)
Section A: Multiple-Choice Questions
1. B
2. A
3. C
4. A
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Chemistry Matters for GCE ‘O’ Level (2 Edition): Full Solutions to Textbook Questions
Chapter 2
Section B: Structured Questions
1. (a)
(b)
(c)
(d)
(e)
(f)
3
100 cm measuring cylinder
3
50 cm gas syringe
3
50 cm burette
3
100 cm beaker
Watch glass
Boiling tube
2. (a) (i)
gas syringe
thistle funnel
concentrated
ammonia solution
quicklime
roundbottomed
flask
sodium
hydroxide
pellets
(ii)
It would contain air.
(b)
dry ammonia gas
collected
gas jar
delivery tube
ammonia
gas
Section C: Free-Response Question
1. (a) (Possible answers)
– To investigate if taking tablets for relieving indigestion with alcohol would affect the speed at
which the tablets work
– To investigate if the addition of alcohol slows down the reaction between indigestion tablets
and water/acid
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Chemistry Matters for GCE ‘O’ Level (2 Edition): Full Solutions to Textbook Questions
Chapter 2
(b) Variable to vary:
– Volume of alcohol added to reaction mixture
Variables to keep constant:
– Volume of water
– Amount of indigestion tablets
– Time taken for the tablet to react with the water and acid
Procedure:
1. Using a measuring cylinder, measure out 25 ml of water each into two conical flasks.
2. Add around 5–10 ml of alcohol into one of the flasks (use a measuring cylinder to measure its
volume).
3. Attach a balloon containing one indigestion tablet to the mouth of each flask using a rubber
band.
4. When the balloon is secure, drop the indigestion tablets into the flasks and start the
stopwatch once the tablets enter the water.
5. Observe the size of the balloons after around 1 minute (or any fixed amount of time).
6. The set-up with the more inflated balloon has produced more gas.
balloon
balloon
rubber band
rubber band
conical flask
conical flask
mixture of alcohol
and water
water
indigestion
tablet
indigestion
tablet
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