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)