Chemistry B Exam Review

VSEPR

the repulsion of electron pairs which may cause different shapes.

Valance shell electron pair reduction, the repulsion of electon pairs surrounding an atom causes the pairs to be oriented as far apart as possible.

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AXe Notation

A= element, X= # of atoms bonded to central atom, E= pair of unshared electrons.

Metallic bonds are

bonds between two metal atoms.

Ionic bonds are

attractions between oppositely charged ions (metal and nonmetal)

covalant bond

a chemical bond that involves the sharing of electron pairs between atoms. Two nonmetals.

Hydrogen bonds are

weaker molecule bonding. Involves Nitrogen, ,oxygen, and flourine. hydrogen bonding is weaker than an ionic or covalent bond

Group

A column on the periodic table (vertical, up & down) determines number of valance electrons

Period

A horizontal row of elements in the periodic table. Shows energy level.

octet rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

duet rule

Hydrogen and Helium only want two electrons

Enthalpy

Measure of heat that is produced or absorbed in a chemicle reaction

Polar dissolves

polar

nonpolar dissolves

nonpolar

Bond strenght least to greatest

Hydrogen, Nonpolar covalant, polar covalant, ionic

Hydrogen bonds and Ice

The hydrogen bonds to the oxygen atoms. causing ice to form. allows ice to be less dense than liquid water.

1 calorie = ____ joules

4\.184

1000 calories = ___ kcal

1 kcal

1000 Joules is _______________ KJ

1 kJ

1000 calories = __ Calories

1 Calorie

STP (standard temperature and pressure)

temp: 0 celcius = 273 kalvin. \n PRessure: 22.4 l \n 22.4 l =

Pressure, temperature, and volume relationships

When pressure goes up, volume goes down: \n volume goes up, temp goes up.

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Daltons law of partial pressure

the total pressure exerted by a mixture of gasses is the same as the particle pressures of all the gasses present. pTotal = P1 + P2.

homogeneous solution

mixture (all parts look the same)

heterogeneous solution

A mixture in which different parts can be easily distinguished

aqueous solution

a solution in which water is the solvent

Solvent

Substance present in the largest amount

solute

other substances in the solution.

Titrations

method of finding normalty of adding another substance with a known molarity. NaVa = NbVb. If finding molarty, convert N to M before doing caluclation so the units are the same

Oxidization

Lose electrons (+)

Reduction

Gains electrons (-)

Arrenenius acid and base

Produces (H+) and (OH-)

Brownsted acid and base

Donates Protron(acid) and accepts protron(base)

what kind of compound is a salt

ionic compound

electronegativity trends on the perioic table are the same as

ionization energy

0-0.4

nonpolar covalent

0\.5-1.7

polar covalent

1\.8+

ionic

nonpolar covalent

electrons shared between nonmetals, often the same element (02), electronegativity differnece 0-0.4

polar covalent

unequal sharing of electrons between nonmentals, electronegativity difference 0.5-1.7

valance electrons

electrons in the outermost energy level, can be found based on group number on the periodic table

pauli exculusion principle

each orbital can have a maximum of 2 electrons and they must have opposite spins

hunds rule

if a sublevel has more than 1 orbital, then the electrons will not “pair up” until all the orbitals have one electron.

Atomic size increases

as you move left and down

ionization energy increases

as you move up and right

chemical activity in metals increases

as you move left and down

chemical activity in nonmentals increases

as you move up and right

electronegativity increases

as you move up and right

delta H

change in enthelapy

to calculate delta H

T Chart:

\-take grams of element/compound in the problem

\-take the molar mass of that compound

\-Put one mole above the molar mass

\-put the number of moles in the problem below and across the 1

\-Put the delta H or KJ of heat above the number of moles in the problem

\-multiply the numbers on top and divide each number in the bottom

specific heat capacity

Q (energy in J) = s (specific heat capacity) x m (mass in g) x (Tfinal-Tinital) (temperature in degrees c)

bond strength

amount of energy needed to break a chemical bond,

triple double single (greatest to weakest)

Hydrogen, Nonpolar covalant, polar covalant, ionic (weakest to greates)

Boyle’s Law

P1V1 = P2V2

inversley related, one goes up other goes down

temperature constant

Charels’s Law

V1/T1 = V2/T2

Directly related, one goes up other goes up

pressure constant

combined gas law

(P1V1)/T1 = (P2V2)/T2

ideal gas law

pv=nrt

r=0.08206, universal gas constant

Dalton’s Law Calculation

\-Find number of moles of each substance using molar mass and t charts

\-Find partial pressures of each using P = nrt/v

\-Add the partial pressures together to find the total pressure

to find kelvin

add 273 to c

to find celcius

subtract 273 from k

concentrated

lots of solute in it

dilute

little solute in it

Molarity =

moles of soulute/liters of soultion

finding mass of the solution using molarity

times the volume by molairty

finding volume of the solution using molairty

divide the mass by the molarity

solubility

how much solute can complelty dissolve in a solvent

saturated

solution that has dissolved all the solute it can at a specific temperature

unsaturated

solution that has NOT dissolved all the solute it can at a specfic temperature

supersaturated

a solution that has more solute dissolved in it than normally possible at a given temperature

solubility usually increases as

the temperature of the solution increases

how to speed up the process of dissolving

\-stir

\-raise the temperature

\-increase the surface area

Absolute zero

0 Kelvin

\-273 Celcius

Acids

\-H+

\-taste sour

\-Ph 0-6

\-Proton Donor

Bases

\-OH-

\-taste bitter

\-Ph 8-14

\-Proton Acceptor

\-Soapy/Slippery

the subscript of H or OH tells

if the acid or base is mono, di, or triprotic.

The larger the subscript, the more acdic or basic the substance will be.

Normality

moles of H or OH/liters of solution

if you already have the molarity

multiply by the mono, di, or tri for the normality (if given normality, divide by these to find molarity)

when doing oxidation and reduction problems

single elements = 0

compounds = charges on pink sheet

Balancing half reactions

2 products = oxidation (smaller to bigger)

1 product= reduction (bigger to smaller)

reactions occur when activation energy is

supplied by collisions

catalysts work by

lowering activation energy

be able to know and label this

exothermic energy diagram

be able to know and label this

endothermic energy diagram

exothermic energy

\-detla H, heat is released

endothermic energy

\+delta H, heat is absorbed

homogeneous equllibrilluim

substances that are present in the same physical state

heterogeneous equllibrilluim

involves substances in more than 1 physical state

noble gases are

not reactive

pressure

the constant bombardment of the walls of a container by the moving molecules of a gas

factors that affect the speed of a reaction

\-nature of reactants

\-temperature of reactants

\-presence of a catalyst

Nuteralized subatances (H20 and salt)

have a ph of 7