(a) Name appropriate apparatus for the measurement of time, temperature, mass and volumes of gases and liquids, including burettes, pipettes, measuring cylinders and gas syringes.
Mass (S.I Unit : kilogram, kg)
- Beam balance
- Electronic balance, with an accuracy of ±0.1g or ±0.01 g (Example: 2.4 g, 2.45 g)
Time (S.I Unit : second, s)
- analogue stopwatch, with an accuracy of ±0.1 s
- electronic stopwatch, with an accuracy of ±0.01 s
Temperature (S.I Unit : kelvin, K)
- Mercury or alcohol thermometer, with an accuracy of ±0.5 °C,
ranging from –10°C to 110°C (Example: 37.5°C)
- Data logger, connected to a temperature sensor. Record data continuously over a time period
- Beaker, measures estimated liquid volume
- Measuring cylinder, measures up to the nearest 0.5 cm3 (Example: 21.0 cm3, 13.5 cm3)
- Burette, measures up to the nearest 0.05 cm3 (Example: 17.00 cm3, 28.95 cm3)
- Pipette, measures fixed volumes of liquid (Example: 20.0 cm3, 25.0 cm3)
- Gas syringes, for measurement of gas volume
(b) Suggest suitable apparatus, given relevant information, for a variety of simple experiments, including drying and collection of gases and measurement of rates of reaction.
(c) State the solubility and density of common gases such as oxygen, carbon dioxide, ammonia, chlorine, hydrogen, hydrogen chloride and sulfur dioxide.
For collection of gas (oxygen, carbon dioxide, ammonia, chlorine, hydrogen, hydrogen chloride and sulfur dioxide), the method depends on gas solubility in water and gas density compared to air.
Gas collection method depends on gas solubility and density
Dry a moist guy by passing it through a drying agent, such as concentrated sulfuric acid, calcium oxide (quicklime), fused calcium chloride
Concentrated sulfuric acid – Dry most gases except alkaline gases
Calcium oxide (quicklime) – Dry alkaline gases, not acidic gases
Fused calcium chloride – Dry most neutral gases, not ammonia gas