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Lab Equipment
In order to complete lab requirement for this course you will learn proper use of a variety of measuring devices (some of which you are already familiar with)
Some of equipment that you may use includes:RulerElectronic balance Graduated cylinderPipetteThermometerpH paper and pH meterColorimeterDissolved oxygen probe
Ruler
There is uncertainty at both ends of
ruler
Electronic Balance
00.0 g.
The uncertainty is
known(± 0.1 g)
✦ plug in balance✦ turn on balance and wait for it to show zero✦ place weigh paper (container) on balance and press zero button ✦ place your sample on weigh paper, wait for reading to stabilize and
record value
Graduated Cylinder
There is only uncertainty at
meniscus
✦ take measurement at eye level✦ measure to bottom of meniscus
Pipette
When rinsing:‣ draw a little air into the pipette
before rinsing with solution‣ wipe the tip of the pipette after
each rinse to avoid contamination‣ rinse the pipette 3 times
‣ choose the appropriate pipette (0.1 ml, 1 ml, 2 ml, 5 ml, 10 ml)
When transferring the liquid:‣ fill the pipette completely‣ lower the meniscus to the line‣ drain the pipette keeping it
upright and in contact with the receiving container
‣ some solution will remain in the pipette (do not expel it)
The uncertainty is
printed on pipette
✦ stir solution with a stirring rod (not thermometer)✦ wait for temperature reading to stabilize (stop changing)✦ record temperature value (estimate value between gradations)
Thermometer
There is only uncertainty at
one end of thermometer
°C°F
✦ suspend thermometer in solution with use of a retort stand (thermometer should not touch container)
pH paper & pH meterpH paper & pH meter
pH paper & pH meter
The uncertainty is
known(± 0.1)
✦ calibrate probe with solutions of known pH✦ measure pH of sample solution
A colorimeter measures absorbance of particular wavelengths of light by a solutionIt can be used to determine relative concentration of a given solute, since concentration of a solute is proportional to absorbance
Colorimeter
The uncertainty is
known(± 0.15)
Dissolved Oxygen Probe
Dissolved oxygen probe can be used to measure oxygen production of photosynthesizing aquatic plant✦ calibrate probe✦ set up photosynthesis kit✦ turn on light and begin logging data
The uncertainty is
known(± 10% of full
scale)