Chapter 1 Measurement in Chemistry
Name: ___________________
Class: ________ (
)
Date: ________________
Lesson Aims
 Name appropriate apparatus for the measurement of time, temperature, mass and
volume.
 State the level of accuracy needed when using common measuring apparatus.
 Suggest suitable apparatus for simple experiments.
 State the purpose of data logging and list examples of its uses.
1.1
Apparatus for Measurement

Measuring Time
Name: Digital stopwatch
SI unit: seconds (s)
Other units: minutes (min), hours (h)
Accuracy in reading: Taken to the
nearest second

Measuring Mass
Name: Electronic
balance
SI unit: kilogram (kg)
Other units: grams (g),
milligrams (mg)
Accuracy in reading:
Up to 0.001 g

Name: Triple beam
balance
Accuracy in reading:
Taken to the nearest
0.1 g
Measuring Temperature
Name: Thermometer
Type: mercury or alcohol
SI units: Kelvin (K)
Other units: degree Celsius (oC) [Commonly Used]
Accuracy in reading: Taken to the nearest 0.5 oC
(either end with .0 or .5 oC)

Measuring Volume of Gases
Name: Gas Syringe
SI unit: m3
Other units: cm3
[commonly used]
Accuracy in reading:
Taken to nearest 1 cm3

Measuring Volume of Solutions
Name:
Measuring
Cyclinder (100 or
250 cm3)
Function:
Measures volume
up to an accuracy
of 1 cm3.
Beaker
Name: Burette
Function:
Measures volume
up to an accuracy
of 0.1 cm3.
Measuring Cylinder
Pipette
Name: Pipette
Function:
Measures and
delivers fixed
volumes such as
10.0, 20.0 or 25.0
cm3.
Burette
Increasing Accuracy in Measurement
The beaker is mainly used for mixing and it is the least accurate of them all.
The pipette is used for fixed volumes. It cannot measure any other volumes accurately.
The burette measures up to 0.1 cm3 and has a maximum volume of 50.0 cm3. It is used to add
variable volumes of solution.
Always include the correct units in the measurements. Marks will be deducted for omission
of units or wrong units.

Meniscus
Meaning: Meniscus is the curved upper surface of a body of liquid.
How to read: Read off the marking touching the bottom of the curve
at eye-level.
Applies for: Measuring cylinder, burette, pipette
Useful website:
http://www.wisconline.com/objects/ViewObject.aspx?ID=GCH302
1.2
Apparatus for Experiments

Heating a Flammable Liquid
Apparatus: Bunsen burner, tripod, wire gauze, boiling tube,
beaker with water (water-bath)
Reason for set-up: The liquid is not heated directly over the
flame to prevent it from catching fire.
Examples of flammable liquid: Ethanol, gasoline, acetone
This set-up is also known as a water-bath and can be used to
measure the boiling point of flammable liquids (below 100 oC).
If the flammable liquid has a boiling point higher than 100 oC,
change the water-bath to oil-bath because oil has a higher
boiling point than water.

Titrations
Titrations are experiments used to find the concentration of an unknown sample of an alkali
solution by measuring the volume of the sample needed to neutralize a fixed volume of acid.
The apparatus needed are burette, pipette, and conical flasks.

Change in Mass During a Reaction
This set-up is used when the reaction produces a gas
that escapes during the reaction.
The gas is formed as the reaction begins, and while it
is escaping, the total mass of reactants in the flask
decreases.
When the mass stops decreasing, it means that no
more gas is produced as one or more reactants has
been used up.
The reason for the cotton wool is to absorb the droplets of chemical solution sticking to the
escaping gas.
Example: Adding marble (calcium carbonate) to hydrochloric acid
Useful website:
http://www.youtube.com/watch?v=1olHaLBnqvY&feature=related

Measuring Volume of Gas from a Reaction
This set-up is used when the reaction produces a
gas that escapes during the reaction.
It measures the volume of gas produced.
The faster the gas is produced, the faster the
reaction.
A stopwatch is used to measure time of gas
production to determine the speed of reaction.

Collection of Gases
The factors to determine the method to collect the gas are density and solubility.
Method: Displacement of water
Properties: For gases insoluble in water
Example: hydrogen, oxygen, carbon dioxide
Carbon dioxide is sparingly soluble in water and some of it will dissolve in water. Therefore
the gas collected will be lesser than expected.
Another method to collect carbon dioxide is by downward delivery.
Method: Upward delivery (Displacement of air)
Properties: For gases less dense than air and soluble in
water
Examples: ammonia
Although hydrogen is insoluble in water, it can also be
collected with this method because it is lighter (less
dense) than air.
Method: Downward delivery (displacement of
air)
Properties: For gases denser than air and
soluble in water
Examples: chlorine, hydrogen chloride, sulfur
dioxide
Although carbon dioxide is insoluble in water, it
can also be collected with this method because
it is heavier (denser) than air.

Separation of Gases During Collection
Acidic gases when passed through concentrated alkali solutions such as sodium hydroxide
solution are removed and not collected.
Alkali gases such as ammonia are removed by concentrated acid solutions.
Soluble gases such as, sulfur dioxide, hydrogen chloride, ammonia and chlorine, are
removed by water.
Water sticking onto collected gas is removed by passing the gas through drying agents. The
end product is a dry gas.
(Drying agents: concentrated sulfuric acid, anhydrous calcium chloride, quicklime)
Less dense
than air
Upward
delivery
Denser than
air
Downward
delivery
Soluble in
water
Displacement
of water
Hydrogen
(H2)
Oxygen
(O2)
Chlorine
(Cl2)
Ammonia
(NH3)
-
Carbon
dioxide
(CO2)
-
Yes
-
Yes
Yes
-
-
-
Yes
-
-
Yes
Yes
-
-
-
Yes
Yes
-
Very low
Low
Low
Very high
High
Yes
Yes
Yes
-
-
Less dense than air
Upward delivery
Denser than air
Downward delivery
Soluble in water
Displacement of
water
Sulfur Dioxide
(SO2)
Yes
Yes
Very high
-
Hydrogen chloride
(HCl)
Yes
Yes
Very high
-
Nitrogen dioxide
(NO2)
Yes
Yes
Very high
-
Removed by water
Ammonia, chlorine, acidic gases (sulfuric dioxide, hydrogen
chloride, nitrogen dioxide)
Removed by concentrated
sodium hydroxide
Carbon dioxide, chlorine, acidic gases
Removed by concentrated
sulfuric acid
Water, ammonia
Removed by anhydrous
calcium chloride
Water, ammonia
Removed by quicklime
(calcium oxide)
Water, acidic gases
Not affected
Hydrogen, Oxygen
Useful website:
http://www.docbrown.info/page13/ChemicalTests/GasPreparation.htm
(A) A wash-bottle containing concentrated sulfuric acid
(B) Drying tower usually with quicklime
(C) U-tube usually with anhydrous calcium chloride
1.3
Data – logging
Data logging can be used to measure and record variables that change over time during an
experiment.
Some variables that can be measured
1. Temperature changes
2. Change in volume of a gas produced
3. Change in mass during a reaction
4. Change in pH as an acid is neutralized by an alkali