1. Experimental Chemistry
Measurements in Chemistry

2. Measurements in Chemistry
Four basic physical quantities measured in Chemistry experiments:
Volume
Temperature
Time
Mass

3. Measurement: Volume of Liquids
The apparatus used depends on:
the volume being measured
how accurate the measurement needs to be
Common apparatus:
Measuring cylinder
Burette
Pipette
Beaker**
Conical flask**

4. Measurement: Volume of Liquids
Measuring cylinder
Only used for measuring approximate volume
Accurate only to the nearest 1 cm3

5. Measurement: Volume of Liquids
Bulb pipette
Measures out precise volumes
EXACTLY 20.0 cm3, cm3 or 50.0 cm3
Used with a pipette filler

6. Measurement: Volume of Liquids
Burette
Long scale: 0 cm3 to 50 cm3
Each graduation is 0.1 cm3
Accurate up to 0.05 cm3

7. Physical quantity to be measured
Other Measurements
Physical quantity to be measured
Apparatus
volume of gases
gas syringe
Measures up to 100 cm3
temperature
thermometer
Accuracy to 0.5°C
time
digital stopwatch
Measures to nearest second
mass of substance
electronic balance
Measures to nearest 0.01 g

8. Apparatus for Chemistry Experiments
Water bath: Heating flammable liquid

9. Apparatus for Chemistry Experiments: Rates of reaction
Change in mass

10. Apparatus for Chemistry Experiments: Rates of reaction
Collecting and measuring a volume of gas
Conical flask VS test tube

11. Collection of Gases
Methods depends on the physical properties of the gas
the solubility of the gas in water
the density of the gas compared to air

12. Collection of Gases: Solubility & Density of Common Gases
Solubility in water
Density compared to air
ammonia
extremely soluble
less dense
carbon dioxide
slightly soluble
denser
chlorine
soluble
hydrogen
not soluble
oxygen
very slightly soluble
slightly denser
sulfur dioxide
very soluble

13. Collection of Gases: Dry Samples
Dry samples can be obtained by passing the gas through a drying agent.
Common drying agents:
concentrated sulfuric acid [✗ ammonia]
quicklime (calcium oxide) [✓ ammonia]
Fused calcium chloride

14. Concentrated Sulfuric acid

15. Quicklime & Fused Calcium Chloride

16. Data Logging