chemistry final

combustion/synthesis (9)

2 or more substances combine to form a single substance (A + B → AB)

decomposition (9)

a single reactant is broken down into 2 or more products (AB → A + B)

single replacement/single displacement (9)

a single element replaces a second element in a compound (A + Bx → B + Ax)

double replacement/double displacement (9)

positive ions between 2 reacting compounds exchange places (Ax + By → Ay + Bx)

combustion (9)

an element or a compound reacts with oxygen (X + O2 → ?)

to predict products… (9)

identify the reaction type and use general formula

to convert moles to particles (10)

moles x (6.022 x 10^23) = particles

to convert grams to moles (10)

grams / molar mass = moles

limiting reagent (11)

determines the amount of product that can be found

excess reagent (11)

the reactant that is not completely used up

theoretical yield (11)

100% of expected mass

actual yield (11)

amount of mass actually formed

5 points of kinetic theory (12)

1. gas is made of particles

2. all particles move in constant random motion

3. all collisions are elastic

4. higher temperature = more energy

5. larger molecules move slower than smaller ones at the same temperature

unit of temperature (12)

273 Kelvin (K) and 0 Celsius (C)

SI unit for pressure (12)

atm

STP (12)

101\.3 kPa or 1 atm & 0 Celsius or 273 Kelvin

absolute zero (12)

point where you have no energy

how is kinetic energy related to temperature? (12)

at higher temperatures there is a wide range of energies, and at lower temperatures the range of kinetic energy is close to the same

how is pressure affected by altitude? (12)

air exerts pressure because of gravity and decreases as you go up in elevation

evaporation (12)

process of turning liquid to vapor (open vessel)

cooling process

vaporization (12)

conversion of a liquid to a gas or vapor

warming process

vapor pressure (12)

force exerted by a gas above a liquid

helps prevent evaporation and boiling

boiling point (12)

the temperature at which a liquid boils

with altitude, boiling point lowers because it needs less kinetic energy

melting point (12)

temperature that a solid turns into a liquid

crystals (12)

solid, orderly, repeating structure

crystal allotropes (12)

carbon = graphite is thin sheets

diamond = tetrahedral shape, rigid compact array

buchminster fullerine = 60 carbon hollow sphere

amorphous solid (12)

solid that does not form crystals

sublimation (12)

changing from a solid to a vapor without changing into a liquid

variables that describe a gas (13)

pressure, volume, temperature, and number of moles

Boyle’s law (13)

(pressure - volume relationship) at constant temperature the volume of a gas varies inversely with pressure

Charles’s law (13)

(temperature - volume relationship) at constant pressure the volume of a gas is directly proportional with temperature

Gay-Lussac’s law (13)

(temperature - pressure relationship) at constant volume pressure is directly proportional to Kelvin temperature of gas

combined gas law (13)

using the three gas la ( ws we are able to see that there is a relationship between pressure, volume, and temperature

hold one of three variables constant

ideal gas law (13)

has 3 of the variables that act on a gas

increase in moles = increase in pressure and volume

Dalton’s law (13)

at constant volume and temperature total pressure exerted by a mixture is equal to the sum of the partial pressures of component gases

Graham’s law of effusion (13)

the rate of effusion of a gas is inversely proportional to the square root of its molar mass

gases of lower molar mass effuse faster

solution (14)

mixture of small particles

solvent (14)

dissolving medium

solute (14)

substance being dissolved

suspension (14)

mixture where the particles will settle out if left undisturbed

mixture (14)

2 or more substances physically combined

colloid (14)

mixture of intermediate sized particles

solubility (14)

amount of solute that can dissolve in a solvent (higher temp = more solubility)

unsaturated (14)

more solute can dissolve in the substance but if more is added it disappears

saturated (14)

no more solute can dissolve but if more is added will sink to the bottom

supersaturated (14)

special situation where solvent holds more solute than it should and requires a series of steps to create

Henry’s law (14)

solubility 1/pressure 1 = solubility 2/pressure 2

electrolytes in solution (14)

(ionic compounds) number of particles is based on the number of separate ions a compound dissolves apart into

nonelectrolytes in solution (14)

(covalent compounds) number of particles per compound and always equal to 1

boiling point eleration (14)

boiling point of a solvent increases when a solute is dissolved in it

freezing point depression (14)

freezing point of a solvent decreases when a solute is dissolved in it

heat (15)

energy that flows from one object to another

Hess’s law (15)

most reactions occur in a series of steps

endothermic (15)

a reaction that absorbs energy and feels cold

equation: A + B + heat → C + D or A + B → C + D AH = +

exothermic (15)

a reaction that releases energy and feels warm

equation: A + B → C + D + heat or A + B → C + D AH = -

heat capacity (15)

the amount of heat required to change the temperature of a given amount of matter by 1 degree

specific heat (15)

the amount of energy required to raise 1 gram of a substance by 1 degree C

spontaneous reactions (15)

free energy (15)

maximum amount of energy that can be used to do useful work

relationship between directly proportional and inversely proportional (13)

inversely proportional has one that goes up and goes down and directly proportional has either both go up or both go down

how to differentiate between colloid and suspension (14)

suspension has multiple phases and colloids have one

colloid uses the tyndall effect and suspension does not

what is conserved in a reaction (11)

mass and particles

spontaneous process (15)

any chemical of physical change that, once begun, occurs with not outside intervention

2 things that determine spontaneous processes (15)

entropy - measure of disorder in a system

enthalpy - the heat of a system when it is under constant pressure

convert moles to volume (10)

1 mol = 22.4 L

5 things that affect the rate of solution (14)

agitation, temperature, surface area, pressure, and saturation

reaction (15)

deltaH rxn

formation (15)

deltaH f degrees = 0

fusion (15)

heat required to melt 1 mol of a substance

solution (15)

deltaH when dissolved

combustion (15)

deltaH of reaction where combustion occurs