Lab 1- Basic Laboratory practices Flashcards
Eye protection
Must always be worn with shatterproof lenses and side shields
Chemicals
Consider them all hazardous unless you are instructed otherwise
Acids and water
Always pour acids into water, and never water into acids
Inserting a tube into a stopper
Lubricate the tube and the stopper’s hole. Holding the rod with a paper towel twist it in and remove excess lubricant
Ring stand orientation
The long edge should be perpendicular to the front of the bench
Recording sheets
Record answers on sheets immediately and independently.
Cleaning up excess
Never return extra reagents to the initial reagent bottle
Stoppers
Hold the stopper in your hand instead of putting it on the counter
Water
Used distilled water unless instructed otherwise
Apparatus
Should never be shared between people
Ideal temperature
Room temperature unless stated otherwise
Proper clothing
Nothing with baggy or loose sleeves
Hot plates vs bunsen burners
Use a hot plate whenever possible
Metric system
Was originally based mainly upon fundamental properties of water because it is one of earth’s most abundant substances
Metric units date
1960 was the international agreement
SI System stands for
The international system of units
Conversion factors and magnitude
Conversion factors have no affect on magnitude
Common scales for modern labritories
Single-pan balances
Graduated cylinders
Tall, cylindrical vessels with graduations scribed on the side. Measure volume
Graduated cylinders best shape
Tall with a small diameter for the best accuarcy
Thermometers
Based upon the principle that liquids expand when they are heated. Mercury or colored alcohol.
1 atm
760 mm Hg (1 torr)
Pipets
Deliever a precisely known volume of a liquid at a given temperature. Always use a rubber bulb when handling
Every measuring device
Has its limitations on its accuracy. Make sure to obtain the information to the highest level of accuracy
Using a graduated cylinder
Measure from the lowest point on the meniscus at eye level. Read to the closest 0.1 mL
Density units
Solid: g/cm^3, Liquid: g/mL Gases: g/L
Precision
Is a statement about the internal agreement among repeated results. How reproducible it is
Arithmetic mean
AKA average. The results is usually taken as the best value
