Laboratory Apparatus, Measurement, Safety Flashcards
Glassware YOU COULD USE in an experiment
use of each
list common laboratory apparatus not made of glass
not glass common laboratory apparatus uses
measure Time
Time can be measured using a stopwatch or stopclock which are usually accurate to one or two decimal places.
The units of time normally used are seconds or minutes although other units may be used for extremely slow reactions (e.g. rusting).
1 minute = 60 seconds.
Generally, reaction times are recorded in minutes or seconds but not both.
A common mistake is to record time in minutes and seconds rather than just in seconds.
measure Temperature
Temperature is measured using a thermometer which can normally give readings to the nearest degree or half degree. Digital thermometers are available which are more accurate.
The units of temperature are degrees Celsius (ºC).
Mass
Mass is measured using a digital balance which normally gives readings to two decimal places. These must be tared (set to zero) before use.
The standard unit of mass is kilograms (kg) but in chemistry grams (g) are most often used.
1 kilogram = 1000 grams
Volume-liquids
For approximate volumes where accuracy isn´t an important factor, ….is used
available in 25 cm3, 50 cm3, 100 cm3 and 250 cm3.
Pipettes are … available in
burettes
For approximate volumes where accuracy isn´t an important factor, measuring cylinders are used. These are graduated (have a scale so can be used to measure) and are available in 25 cm3, 50 cm3, 100 cm3 and 250 cm3.
Pipettes are the most accurate way of measuring a fixed volume of liquid, usually 10 cm3 or 25 cm3.
Burettes are the most accurate way of measuring a variable volume of liquid between 0 cm3 and 50 cm3 (e.g. in a titration).
draw a burette
draw conical flask
draw pipette filler
draw volumetric /bulb pipette
Burettes have an accuracy of….which means that when you are….
Burettes have an accuracy of 0.1cm3 which means that when you are taking a burette reading it should be done to one decimal place, i.e. 25.1cm3 and not 25 cm3.
Measuring cylinders are used to measuring… and have an accuracy of….
Measuring cylinders are used to measuring larger volumes and have an accuracy of 2cm3.
measure Volume-gases
A gas syringe is usually the apparatus used.
A graduated cylinder inverted in water may also be used, provided the gas isn’t water soluble.
If the gas happens to be heavier than air and is coloured, the cylinder can be used upright.
draw Diagram of the set-up for an experiment involving gas collection
Safety
Questions on safety ask you to determine:
The source of the risk
The precaution you recommend taking
The reason for the precaution
they are six
