exam (II)

avogadro’s number

6\.02 x 10^23

molar mass

quantity in grans that = atomic mass of an element

chemical change

occurs when a substance is converted into 1 or more new substances that have different formulas and properties

signs of a reaction

bubbles, change in color, smell, temperature

delta sign (△)

heat is used to start the equation

balanced chemical equation

no atoms are lost or gained; number of atom are equal on both sides

combination reactions

2 or more elements form one product; A+B = AB

decomposition reaction

one substance splits into 2 or more simpler substances; AB = A+B

simple replacement reaction

one element takes the place of a different element in another reacting compound; AB+C = AC + B

double replacement reaction

positive ions in the reactant compounds switch places; AB +CD = AD + BC

combustion reaction

carbon-containing compound burns an oxygen gas to form carbon dioxide and water

incomplete combustion

when oxygen supply is limited, incomplete combustion occur

carbon monoxide

colorless, odorless, poisonous gas

oxidation-reduction reaction

provides us with energy from food; provides electrical energy in batteries

oxidation

involves loss of electron; + oxygen; - hydrogen

reduction

involves gain of electron; - oxygen; + hydrogen

OIL

Oxidation Is Loss of electron

RIG

Reduction Is Gain of electrons

law of conservation of mass

matter cannot be created or destroyed; no change in total mass occurs

mole-mole factors

a ratio of the moles for any two substances in an equation

3 conditions for a reaction to occur

collision: reactant must collide

orientation: reactant must align properly to break and form bonds

energy: collision must provide the energy of activation

exothermic reaction

heat is released; energy of product is less then the energy of the reactant

endothermic

heat is absorbed; the energy of the products is greater than the energy of reactants

reaction rate

speed at which reactants is used up; speed at which products forms; increase in temp = reacting molecules move faster; increase speed with concentration of reactants

catalyst

increase rate of reaction; lower the energy activation; not used during the reaction

factors that increases reaction rate

1. temp - increase collision, increase collision w/ energy of activation
2. increase reactant concentration - more collision
3. adding catalyst - decrease energy of activation

kinetic molecular theory

a gas consists of small particles that:

move rapidly in a straight line

have no attraction/repulsive forces

very far apart

very small volumes compared to the volume of the container they occupy

kinetic energy that increase with an increase in temp

pressure (p)

forces exerted by a gas against the walls of the containers; atm, mmHg, Torr, Pa

volume (v)

space occupied by a gas; L, mL

temperature (T)

determining factor of the kinetic energy of the gas particles; degree celsius, kelvin

amount (n)

quantity of gas present in a container: g, n

volume (def.)

increase with an increase in the temperature at a constant pressure

temperature (def.)

relates to the average kinetic energy of the molecules and is measured in kelvin temp. scale

pressure

the measure of the gas particle collisions with the sides of a container and is measured in units of mmHg, Torr, atm, Pa, kPa, PSI

atmospheric pressure

gas particles in the air exert pressure on us; decreases as altitude decreases, 1 atm at sea level; changes with the weather and altitude

barometer

measured the pressure exerted by the gases in the atmosphere; indicates atmospheric pressure as the height to millimeters of the mercury columns; 1 atm = 760mm high in barometer tube

units for atmosphere

atm; 1 atm

units of millimeters of Hg

mmHg; 1 atm = 760 mmHg

units for Torr

torr; 1 atm = 760 Torr

units for inches of Hg

inHg, 29.9 Hg

units for pounds per square inch

psi

units for pascal

Pa; 1 atm = 101,325 Pa

units for kilopascal

kPa; 1 atm = 101.325 kPa

boyle’s law

volume decrease, pressure increases; p1 v1 = p2 v2

pressure of a gas is inversely related to its volume when T is constant

kinetic energy theory

motion (kinetic energy) of the gas particles will also increase

increase in temp. = gas particle movement increases

amt. and pressure of the gas help constant, the volume of the container will increase

charles’s law

kelvin temp. of gas is directly related to the volume; v1/t1 = v2/t2; gas increase = volume increase

gay-lussac’s law

kelvin temp. of gas doubled and the volume amt. of gas does not change, pressure also doubles; p1/t1 = p2/t2; k doubles = p doubles

combines gas law

pressure, volume, temp relationship for gas; p1v1/p2 = p2v2/p2

avogardo’s law

volume of gas is directly related to the number of moles of gas; v1/n1 = v2/n2

standard temperature and pressure (STP)

volume of gas can be compared @ STP, when they have same temp and pressure

standard temperature

0 degree celsius or 273K

standard pressure

1 atm (760 mmHg)

molar mass

a mole of gas occupies a volume of 22.4L

partial pressure

pressure that each gas in a mixture would exert if it were by itself in the container

dalton’s law of partial pressures

pressure depends on a total number of gas particles, not on types of particles

the ideal gas law

PV=nRT

“R”

0\.0821 L(atm)/mol(K)

partial pressure

Pa= XaPt

Xa

mol fraction of n; mole A / total mole

solutions

a homogeneous mixture of 2 or more substances;

2 components: solvent and solute

solutes

present in a smaller amount;

maybe liquid, gases, or solids;

mix w/ solvent;

spread evenly throughout the solutions

water (solvent)

universal solvent;

polar

solutions formation

both solute and solvent are polar or both non polar; not polar-nonpolar

strong electrolytes

dissociates 100% in water, producing positive and negative ions

weak electrolytes

dissociates only slightly in water; forms a solution with a few ions and mostly ions from undissociated molecules

nonelectrolytes

dissolves as molecules in water; does not produce ions in water, do not conduct an electrical current

solubility

the maximum amount of solute that dissolves in a specific amount of solvent; expressed as grams of solute in 100 grams of solvent, usually water

unsaturated solutions

contain LESS THAN the max amount of solute; CAN DISSOLVE more solute

saturated solutions

contain MAX AMT of solute that can dissolve; may HAVE UNDISSOLVED SOLUTE at bottom of container

effects of temperature on solubility

depends on temp.

most solids increase as temp. increases

gasses decreases as temp. increases

concentration of solutions

amount of solute/ amount of solutions

units of concentration

mass percent (m/m)

volume percent (v/v)

mass/volume (m/v)

molarity (moles solute/liters solutions)

mass percent

g of solute / g of solute + g of solvent x 100

\
g of solute / 100 g of solution

volume percent

mL of solute / mL of solution x 100

\
mL of solute / 100 mL of solution

mass/ volume percent

g of solute/ mL of solution x 100

\
g of solute / 100 mL of solution

molarity

the moles of solute per volume (L) of solution;

moles of solute / liter of solution

dilution

water is added; volume of solution increases; concentration decreases; mass of solute in the solution remains the same

solute concentration

in the intial and diluted solutions moles of solute is the same

for (%) concentration

C1 V1 = C2 V2

for molarity

M1 V1 = M2 V2

molarity in chemical reactions

molarity x mole / 1 L x volume (L) = moles

\
moles x 1 L /moles = volume (L)

solutions

transparent, do not separate, contain particles, ions, or molecules that cannot be filtered and pass through semipermeable membrances

colloids

medium-sized particles, cannot be filtered, can be separated by semipermeable membranes

suspensions

heterogeneous, non-uniform mixtures; very large particles that settle out of solution; can be filtered, must be stirred to stay suspended

osmosis

water (solvent) flows from a lower to a higher solute concentration; level of the solution with the higher solute concentration rises; concentration of the two solution become equal with time

osmotic pressure

equal to the pressure that would prevent the flow of additional water into the more concentrated solutions; greater than the number of dissolved particles in the solution increases

osmotic pressure II

hydrostatic pressure required to prevent the net flow of water through a semi-permeable membrane solutions

\
IIV = nRT

“M”

total particle molarity or osmolarity

isotonic solution

exerts the same osmotic pressure as body fluids such as red blood cells (RBCs)

hypotonic solution

has a lower solute concentration; water flows into cells by osmosis

hypertonic solution

higher solute concentration; means water flows out of cell by osmosis

hemolysis

increase in fluid causes the cells to swell and burst increase

crenations

RBCs shrink in size

dialysis

solvent and small particles pass through an artificial membrane; large particles are retained inside; waste particles such as urea from blood are removed using hemodialysis

acids

molecular substances that produce ions

acids (arrehenius)

produces hydrogen ions when they dissolve

electrolytes

sour taste

turns blue litmus paper RED

corrodes same metals

naming acid

“-ate to -ic acid” or “-ite to -our acid”

2 categories that bases falls into

1. ionic compounds containing hydroxide ions in water
2. molecular compounds that react with water to produce hydroxide ions

bases (arrehenius)

produces hydroxide ions (OH-) in water

taste bitter or chalky

also electrolytes

feels soapy and slippery (dissolves layers of skin and cause to slip past)

turn litmus paper BLUE

naming bases

\+ hydroxide