Experimental chemistry

• Measurement of time

  SI unit- seconds (s)

  other units- minutes (min), hours (h)

  apparatus- digital stopwatch and analog stopwatch
• Measurement of temperature

  SI unit- kelvin (k)

  other units- degrees celsius (°C)

  Apparatus- thermometer
• Measurement of length

  SI unit- metre (m)

  other units- millimetre (mm), centimetre (cm), decimetre (dm)

  apparatus- metre rule and measuring tape
• Measurement of mass

  SI unit- kilograms (kg)

  other units- grams (g), miligram (mg), tonnes (t), kilo tonnes (kt)

  apparatus- beam balance and electronic balance
• Measurement of volume

  SI unit- cubic metre (cm^3)
• Apparatus:

  volumetric flask- accurate fixed volumes that are larger e.g. 100 cm^3 or 250 cm^3

  measuring cylinder- a range of volumes to the nearest 0.5 cm^3 e.g. 31.5 cm^3 or 23.0 cm^3
• pipette- accurate fixed volumes e.g. 10.0 cm^3 or 25.0 cm^3

  burette- a range of volumes to the nearest 0.05 cm^3 e.g. 31.55 cm^3 or 23.00 cm^3
• We can use a gas syringe to measure the volume of a gas. Typical gas syringes in the laboratory measure volumes up to 100cm^3
• Displacement of water - suitable for collecting gases that are insoluble in water

  e.g. carbon dioxide, hydrogen and oxygen
• Downward delivery- collect gases that are soluble in water and denser than air

  e.g. chlorine, hydrogen chloride
• Upward delivery- collect gas that is soluble in water and less dense than air.

  E.g. ammonia, hydrogen