labratory equipment Flashcards
What is a beaker? (def)
A wide open container with a flat bottom (made out of glass or plastic)
What is a beaker used for?
Used to mix, heat, or hold substances
What does a graduated beaker do
Give approximate measurements of liquid volumes
The top rim of a beaker has a ____ and a ____ indentation that allows liquids to be easily poured from it
lip
curved
What is a flask? (definition)
a glass container with a thin neck and a rounded base
What are flasks used for?
To measure, heat, or store liquids
What does the neck of the flask allow?
Clamps to be attatched or stoppers to be placed
List the three different types of flask
- erlenmeyer flask
- florence flask
- volumetric flask
Describe an erlenmeyer flask (3)
- cone shaped base
- often used during filtration/titration
- wide bottom allows liquids to be heated quickly
which type of flask is often used in the processes of filtration and titration?
(process where solid particles removed from fluid by filter medium/process where a solution with a known ratio of parts is used to determine how much of a part there is in another solution)
Erlenmeyer flask
describe a florence flask (3)
- round/spherish flask with a rounded or flat base.
- liquid contained heats evenly due to shape
- stronger than other flasks.
Which flask is used to boil liquids for distillation (liquid vaporized then condensed for separation) processes and can handle extreme temps/temp changes?
florence flask
Describe a volumetric flask (3)
- pear shaped/raindrop base, long neck
- usually with a stopper
- always marked to hold a specific amount, and only that amount
Which flask is used to accurately measure liquids to a fixed volume or to create solutions with fixed volumes?
Volumetric flask
What is a test tube? (definition)
A cylinder glass tube with a rounded bottom
What is a test tube used for?
Holding or heating small amounts of a substance
How is a test tube held?
Held upright using clamps or test tube holders
What is a buret/burette?
long glass cylinder used to measure and dispence an amount of liquid
What does a burette look like?
Cylinder open at top, bottom comes together into tip. Stopcock valve attatched to bottom, above tip, which regulates amount of liquid flowing
Burettes are often used for _____ with an Erlenmeyer flask below the tip of the buret,
titrations
What is a graduated cylinder?
A tall cylinder used to measure volume of a liquid
Volume of a liquid in a graduated cylinder is measured from the _____
bottom of the meniscus
What is a meniscus?
An inward curve at a liquid’ surface
What are graduated cylinders often used to measure besides liquids?
The volume of an irregular solid (through displacement)
Mass is measured by devices known as _____
balances
What do balances do?
measure mass by comparing the unknown mass of an object to the known mass of another object
How does a triple beam balance measure mass?
compares an object’s mass to the mass of predetermined weights (riders)
The triple beam balance has a pan connected to ___ beams marked with certain measurements, each carrying a different ____ (____) with a known mass. On the other end of the beams is a __, which shows when the device is balanced
three
riders
pre-determined weight
pointer
To measure the mass of the object on the pan (triple beam balance), predetermined weights moved across beam until pointer shows that ____. _______ on all 3 beam balances is the mass
the riders and the object on the pan are balanced
Total sum of the values the riders stopped at
What is an analytical balance?
A single pan balance that is electronic. pan enclosed within deice.
How is mass measured in an analytical balance?
Empty container mass measured, then mass of substance in container measure. Mass together - empty container mass = mass of substance.
What is the tare and tare weight?
Tare = mass of empty container
tare weight = weight of empty container
What is taring?
Taring is when the mass of a substance is measured by substracting the mass of the container from the mass of both the container and substance
What is a thermometer (if you don’t get this right, so help me-)
thin graduated glass tube used to measure temperature.
-bulb on one end that holds a fluid that expands when heated.
Markings on thermometer generally dictated by two reference points, the ___ and ____
freezing point of water
boiling point of water
What do digital thermostats measure temp using? What does that thing have?
Thermistors, which contain a semiconductor substance (conducts electric current well at high but not low temps). Microchip measures how much electrical current. converts into temp movement
What device is used to measure the pressure of a fluid?
Manometer
Manometers are usually used to measure pressures close to _____
atmospheric pressure
How do manometers measure pressure? What is Po? What is Pa? What is H?
Based on the height difference between the liquid in two legs of the “U” shape. The two different legs are hooked up to two different pressure sources.
- Po is the reference pressure (pressure in the leg exposed to atmosphere)
- Pa is the test pressure, or the pressure of the leg where the pressure you are testing is.
- H is the difference between Po and Pa
What is a barometer?
A type of manometer used to measure atmospheric pressure
Mercury barometers are often used in ____
weather reporting
Most pressure gauges today are ____. They have a _____, which ____ when pressure increases, and turns a pointer as it ____.
Aneroid (without fluid)
coiled tube (bourdon tube)
contracts like a spring
coils and uncoils
Who developed the first mercury barometer? What unit of pressure is named after them?
Evangelista Torricelli
the Torr
What is a pipette?
A device used to measure liquids and move them between containers
How is a liquid drawn into a pipette?
Suction as a vacuum is created within the pipette
Name the two different kinds of pipette
Pasteur pipette and volumetric pipette.
What is a Pasteur pipette? Is it accurate?
A long skinny tube with a bulb at one end (looks like an eye dropper). Does not do accurate measurements
What is a volumetric pipette? Is it accurate? Do they come in different sizes
A long skinny tube with a wider bit in the middle and a suction thing at an end.
Accurately measure a specific volume of liquid.
Come in different sizes
What is a bunsen burner?
A gas burner with a single steady flame
Where does the flame burn on a bunsen burner?
Above a vertical metal tube connected to a gas source
What is the “collar” on a bunsen burner?
The collar controls the amount of air that mies with fuel, and as such, affects the quality of the flame. Can be rotated to change amount of air.
What is the “valve” on a bunsen burner?
A valve controls the amount of air that flows into the bunsen burner
How are the collar and valve of a bunsen burner in relation to each other (physically)?
The valve is slightly beneath (?) the collar. The valve looks like a long screw while the collar looks like a tube of metal
What is a crucible? (def)
A special high temp porcelain container used to melt metals, to dry powders, or accomplish other high temp tasks
What are tongs used for?
To hold onto hot containers and crucibles
What is a stopper? (definition)
A rub top that fits into a flask or test tube.
Sometimes closed and other times have small holes for fitting into other equipment
What is a funnel? (definition)
Cone shaped objects with stems.
Used to pour liquids from one container to another
What is a burette stand?
A stand that holds a burette in place with a clamp
What is a ring stand?
A circle of metal attached to a stand that can hold beakers or flasks in the air when supported by wire gauze or a clay triangle.
What is a hot plate?
A device for heating things without an open flame
controlled by a dial
What is a double pan balance?
A device used to compare the weights of two different objects
