chem 121 lab final

monomer

a building block of a macromolecule; a single, repeating unit. binds together to make polymers

molecular compound

contains only nonmetals

ionic compound

contains a metal (cation) and a nonmetal (anion)

sodium polyacrylate

absorbs 100-1000 times its mass in water, used in diapers, pet potty pads, and medical bandages

sodium alginate

used in jelly

acetic acid

the name of the acidic component of household vinegar

end point

visual color change of the solution

equivalence point

the theoretical end of the titration; signifies moles of analyte and moles of titrant are equal

.01mL

a burette should be read to the nearest…

molarity

mols divided by liters

sigma bond

each binding domain is classified as one…

pi bond

any additional bond on top of a sigma bond is classified as…

valence shell electron pair repulsion

what does VSEPR theory stand for?

combination

A + B -> AB

decomposition

AD -> AB + C

single displacement

AC + B -> A + BC

metathesis

AC + BD -> AD + BC

redox

A -> A^n+ + n e-

B + m e- -> B^m-

——-

A + B -> A^n+ + B^m-

toxic and corrosive

examples include NaOH, HNO3, H2SO4

driving forces

formation of a gas, a ppt, or a weak/non-electrolyte as one of the products

metathesis reaction

an aqueous chemical rxn in which the cations and anions of the rxn change partners

neutralization reactions

form water and salt as products

non-electrolytes

molecular compounds are considered …

electrolytes

soluble ionic solids, strong acids/bases

weak electrolytes

weak acids/bases

actual/theoretical x 100%

percent yield equation

filtration

separating a mixture through a porous sheet, typically a mixture of a solid and a liquid

NaCl

what was the filtrate in beaker A for lab 2

moved with tongs onto a hot pad

how should hot objects be handled in a lab

accuracy

how close your measurements are to the actual amount

precision

how close your measurements are to each other

gravimetric determination

a quantitative method for accurately determining the amount of a substance

sublimation

the process when a solid turns into a gas, bypassing the liquid phase

.001g

record a measurement using an analytical balance to the nearest…

.01mL

record your measurement using a pipet to the nearest…

±2 degrees C

when measuring using a thermometer, record to the nearest

density

mass/volume

mixture

a substance made by combining two or more pure substances in a way that no chemical rxn occurs

pure substance

an element or compound, fixed composition and is able to be defined by a single chemical formula

chemical properties

reactivity, flammability, and solubility. those that can be observed and measured by performing change to the chemical composition of the compound

physical properties

boiling point, melting point, solubility, and density. those that can be observed without changing the chemical composition of the component substances themselves

extraction

the process used to purify or isolate a substance. this process selectively removes a compound of interest from a mixture based on its solbulity in a particular solvent

decantation

The separation of a liquid from a solid by pouring

residue

the solid left on the filter paper

filtrate

the liquid that passes through

volumetric determination

The amount of analyte is determined by measurements of solution volumes that react with the analyte

drying the sample

The water must be removed prior to sample preparation as results are generally reported on a dry sample weight basis these are dried by placing them in an oven

sample preparation

A small amount of acid is usually added to the solution to prevent precipitation of compounds that would interfere with the analysis

washing the precipitate

Aqueous ions present in the solution will absorb to the surface of the precipitate due to electrostatic attraction. If these ions are not removed, they will be weighed with a precipitate and give it high result for the analysis. Deionized water or dilute acid solution solutions are most commonly used.

standardization

determining molar concentration

titration

The process of slowly, adding one solution to another until the reaction between the two is complete

indicator

A solution that changes color depending on the pH of the solution

linear

electron domain geometry: 2

molecular: 2-0

trigonal planar

e domain: 3

molecular: 3-0

trigonal planar, bent

e domain: 3

molecular geometry: 2-1

tetrahedral

e domain: 4

molecular: 4-0

tetrahedral / trigonal pyramidal

e domain: 4

molecular: 3-1

tetrahedral / bent

e domain: 4

molecular: 2-2

trigonal bipyramidal

e domain: 5

molecular: 5-0

trigonal bipyramidal / seesaw

e domain: 5

molecular: 4-1

trigonal bipyramidal / t-shaped

e domain: 5

molecular: 3-2

trigonal bipyramidal / linear

e domain: 5

molecular: 2-3

octahedral

e domain: 6

molecular: 6-0

octahedral / square pyramidal

e domain: 6

molecular: 5-1

octahedral / square planar

e domain: 6

molecular: 4-2