AP Chemistry Unit 4

physical change

occurs when a substance undergoes a change in properties but not a change in composition. Matter changes form, but not chemical identity

Phase changes or forming solutions

what are some common physical changes? (2)

chemical change

occurs when substances are transformed into new substances, typically with different compositions. A change that creates new substances by the breaking of bonds and the formation of new bonds

heat , light, temp. changes, formation of a new substance, odor, color

Evidence for Chemical change (name at least 3)

intermolecular

In the case of a phase change, bonds are not broken or formed, but what forces can be severed or formed?

equal

any representation of a chemical change must contain _________ numbers of atoms of every element before and after the change occurred

molecular equation

a complete balanced equation representing all reactants and products in a chemical reaction.

complete ionic equation

a complete balanced equation which separates all ions that participate in the chemical reaction

net ionic equation

Includes only the species involved in a chemical reaction, does not include spectator ions

titration

a measured amount of a solution of unknown concentration is added to a known volume of a second solution until the reaction between them is just complete

analyte

Titrations may be used to determine the concentration of an ______________ in solution.

titrant

The solution of known concentration; has a known concentration of a species that reacts specifically and quantitatively with the analyte

equivalence point

occurs when the analyte is totally consumed in a titration. Often indicated by a change in a property (such as color) that occurs when it is reached

endpoint of titration

The point in a titration where the acid and base have completely reacted with one another. It is usually accompanied by an indicator's change in color

analyte

The solution of unknown concentration

buret

a piece of laboratory glassware used to add small volumes of liquid to a solution

acid-base reaction

involves transfer of one or more protons between chemical species.

Oxidation-reduction reaction

involve transfer of one or more electrons between chemical species, as indicated by changes in oxidation numbers of the involved species

Combustion

an important subclass of oxidation-reduction reactions, in which a species reacts with oxygen gas. In the case of hydrocarbons, carbon dioxide and water are products

redox reaction

electrons are transferred from the species that is oxidized to the species that is reduced.

oxidation number

Positive or negative number that indicates how many electrons an atom has gained, lost, or shared to become stable (relates well to charge in ions)

precipitation reaction

frequently involve mixing ions in aqueous solution to produce an insoluble ionic compound

all sodium, (Na+) potassium, (K+) ammonium, (NH4+) and nitrate salts (NO3-) (SNAP)

what are soluble in water?

example of precipitation reaction

AgNO3(aq) + KCl(aq) →AgCl(s) + KNO3(aq)

0

oxidation rule #1: Elements in their elemental form have an oxidation number of...

charge

oxidation rule #2: The oxidation number of a monatomic ion is the same as its...

-2, -1

oxidation rule #3: Oxygen has an oxidation number of ______, except in the peroxide ion (O22-), in which it has an

oxidation number of ______.

-1, +1

oxidation rule #4: Hydrogen is ___ when bonded to a metal, _____ when bonded to a nonmetal.

-1

oxidation rule #5: Fluorine always has an oxidation number of...

negative, oxyanions

oxidation rule #6: The other halogens have an oxidation number of -1 when they are ________________. They can have positive oxidation numbers, most notably in ______________

neutral

oxidation rule #7: The sum of the oxidation numbers in a __________ compound is zero.

ion

oxidation rule #8: The sum of the oxidation numbers in a polyatomic ion is the charge on the _______.

Acid-Base

What type of reaction occurs when ammonia reacts with water?

Precipitation Reaction

What type of reaction occurs when cadmium nitrate reacts with potassium phosphate?

oxidation

loss of electrons is...

reduction

gain of electrons is...

Bronsted-Lowry acid

a proton donor substance

Bronsted-Lowry base

a proton acceptor substance

conjugate acid

the substance that forms after a base gains a proton

Conjugate Base

the substance that remains after an acid has donated its protons

HCl, HBr, HI, HNO3, H2SO4, HClO4, HClO3

seven strong acids

amphiprotic

water is...( in terms of being a proton donor or acceptor)