Chem Lab midterm

Always wear __

appropriate PPE- long sleeves and long pants, closed toed shoes, hair up and goggles, gloves if necessary

buret

dispensing and transferring known volumes of fluids- used in titrations and rounded to 4 sig figs

pipet

Used to dispense small quantities of liquids- volumetric 4 sig figs

graduated cylinder

instrument used to measure volume of a liquid- read at eye level (3 sig figs)

thermometer

measures temp- 3 sig figs

balance

measures mass, zero before use write down all sig figs balance displays

mass water delivered

mass= volume - density

volume delivered

from equipment

percent error

experimental value- theoretical value/ theoretical multiplied by 100

solution

A homogeneous mixture of two or more substances

solute

A substance that is dissolved in a solution.

solvent

A liquid substance capable of dissolving other substances

standard solution

a solution whose concentration is accurately known

Precision

consistency of measurements

Accuracy

how close a measurement is to the true value

limiting reactant

the substance that controls the quantity of product that can form in a chemical reaction ( completely consumed)

excess reactant

the substance that is not used up completely in a reaction

precipitate

A solid that forms from a solution during a chemical reaction.

filtrate

liquid that has passed through a filter

ideal gas law

PV=nRT or p1v1=p2v2 or p1/t1=p2/t2

outlier

A value much greater or much less than the others in a data set

calibration curve

A graph showing the value of some property versus concentration of analyte. When the corresponding property of an unknown is measured, its concentration can be determined from the graph.

salt

ionic compound

hydrate

A compound that has a specific number of water molecules bound to its atoms

anhydrous

without water

Hygroscopic

a term describing salts and other compounds that remove moisture from the air

efflorescent

loses water to air

What does the buret measure to?

0.05 ml, total 50 ml

What does the beaker measure to?

can be 400ml, 200 ml etc. can be marked every 50, or every 10

What does the graduated cylinder measure?

can be 100 or 10 ml, either every 1ml or .1

Volumetric flask

for making up solutions to a known volume

What does a pipette measure to

10 ml exactly

Erlenmeyer flask

used to hold liquids, has narrow neck to prevent splashes