This document discusses measurement in chemistry, including units and apparatus used to measure mass, volume, temperature, and time. It describes common laboratory tools like balances, measuring cylinders, burettes, pipettes, thermometers, and stopwatches that are used to measure the mass of substances, volumes of liquids and gases, temperature of substances, and time taken for reactions according to standard SI units. The objectives are to name appropriate measurement apparatus and suggest suitable equipment for simple experiments involving collection of gases.

1. Measurement in ChemistryChapter 1

2. Lesson ObjectivesName appropriate apparatus for the measurement of time, temperature, mass and volume, including burettes, pipettes, measuring cylinders and gas syringesSuggest suitable apparatus, given relevant information, for a variety of simple experiments, including collection of gases

3. IntroductionIn order to communicate effectively, scientists all over the world use the International System of Units (S.I. units) as a common standard for their measurements.In laboratory, measurements are usually carried out to find the following:Mass of substancesVolumes of liquids and gasesTemperature of substancesTime taken for reactions

4. (a) Measuring MassThe S.I. unit for mass is the kilogram (kg).Common apparatus used to measure mass:

5. (b) Measuring VolumeThe S.I. unit for mass is the cubic metre (m3).The commonly used units for volume in laboratory are centimetres (cm3) or decimetres (dm3).i.e. 1 dm3 = 1000 cm3BeakerMeasuring Cylinder

6. (b) Measuring Volume - LiquidsCommon apparatus used to measure volumes of liquids:

7. (b) Measuring Volume - LiquidsSolution when placed in a glass container will form a curved surface called a meniscus.If the meniscus is concave, read off the scale at the bottom of the meniscus. If the meniscus is convex, read off the scale at the tope of the meniscus instead.Concave meniscusConvex meniscus

8. (b) Measuring Volume - GasesGases can be collected and measured using the set-up shown below.Common apparatus used to measure volumes of gases:

9. (c) Measuring TemperatureThe S.I. unit for temperature is Kelvin (K).The commonly used unit for temperature in laboratory is degree Celsius (ºC).Common apparatus used to measure temperature:

10. (d) Measuring TimeThe S.I. unit for time is second (s).Common apparatus used to measure temperature:

11. Objectives ChecklistName appropriate apparatus for the measurement of time, temperature, mass and volume, including burettes, pipettes, measuring cylinders and gas syringesSuggest suitable apparatus, given relevant information, for a variety of simple experiments, including collection of gases