CHEMISTRY

Kinetic Molecular Theory States

• the entities in s, l, g are in constant random motion

• = they collide with each other

• → kinetic molecules energy

  • Energy object has due to motion

Translational

• movement of particle through space on a linear path

Rotational

• spinning in place

vibrational

• back + forth vibrations

What motion does a solid’s particles have? Strength? uniform?

• vibrational, strong, very uniform

What motion does a liquid’s particles have?

• all 3, mid, mid

What motion does a gas’s particles have? strength? uniform?

• all three

• weak

• not uniform

Atmospheric Pressure

• force per unit area exerted by air on all objects

Galileo Galili and Toricelli

• put tube in tank of Hg

• = created barometer + explained atomospheric pressure

Robert Boyle

• Added mercury to J tube

• when pressure increased the height of Air trapped in the tube decreased

• = pressure and volume are inversely proportional when temperature is constant

Charlies

• discovered relationship between temperature and volume

• put a tube of Hg in a cold tank and another in a hot tank

• hotter = mercury moved up the tube

• when pressure is constant: volume & temperature are porpotional

  • not direct

• 1 degree increase = 1/273 increase in volume

• K = 273 degrees C

Gay-Lusssac

• discovered relationship between pressure and temperature when volume is constant

• directly proportional

• discovered law of combining volumes

  • = when gases react the volumes of the reactants and products are in whole number ratios at constant pressure and temperature

Dalton

• Law of multiple proportions

  • masses of elments combine in whole number ratios

• Law of partial pressures

  • total pressure = pressures of all gases

Avagadro Gas Law hypothesis

• Equal volumes of ideal gases at the same temperature and pressure contain the same number of molecules

  • = 1 mol of a gas occupies same space as = 1 mol of a diff gas at the same temp and pressure

Molar Volume

• Under Standard Temperature and Pressure (STP) 1 mol of any ideal gas will occupy a volume of exactly 22.4L

Ideal gas law

• states that an equal volume of gas at the same temp and pressure contain an equal number of molecules

  • v porotional to n

• Combine with other laws

  • = PV =nRT

Solution

• homogenous mixture

• 2 or more substances

• uniform

• can be solid liquid or gas

Fun facts about water

• very polar

  • hydrogen bonds & asymmetrical arrangement

• special dipole-dipole force

  • provides the stickiness needed for water to be liquid at room temp

• high melting + boiling point

• high surface tension

• expands when cooling

• immiscible w/ non-polar compounds

Intramolecular forces

• attractive forces within a molecule

• Strong

Intermolecular forces

• attractive forces between molecules

• London dispersion > dipole-dipole > hydrogen bonding

• Weak

How does water dissolve ionic compounds

• water is very polar

• uses its positive and negative sides to isolate the ions and surrounds them fully

Hydration

• process where ions are surrounded by water molecules

Dissociation

• seperation of ions when the compound dissolves

• NOT A CHEMICAL REACTION

Dissasocitaion

• solid → aq + aq

• polyatomic atoms stay together

Dissolving molecular compounds

• = if polar → it will dissolve (like dissolves like)

• attractive forces between solvent and solute are stronger than attractive forces within the solute

Surfactants

• Substance that acts on the surface of a liquid

  • reduces surface tension

    • breaks down the hydrogen bonding on the surface

  • allows oil and water to mix

Properties of acids

Corrosive (means breaks down certain

substances)

 To many fabrics, paper & skin

þ React with some metals

 think of activity series, any metal above hydrogen

 Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g)

þ React with carbonates (CO32-) & bicarbonates

(HCO3-) to produce CO2(g)

 CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)

þ React with bases to form a salt & water

Properties of bases

Corrosive (sometimes referred to as

caustic)

 To many fabrics, paper & skin

þ Can react with oils and fat to

produce soap

 Saponification

þ React with CO2(g) to form carbonates

 Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l)

þ React with acids to form a salt & water

Arrhenius theory of Acids & Bases

Acids – produce H+ ions in water

Bases – produce OH- ions in water

What happens to a base in water

• base is an ionic compound that dissociates into cations and hydroxide ions, OH-,

What happens to an acid in water

• Acid is a

molecular compound that ionizes to produce

hydrogen ions, H+(aq) in water.

• For example, the ionization equation for nitric

acid is HNO3(aq) → H+(aq) + NO3-(aq

Ionization

• involves the formation of ions from uncharged molecules

  • Previously uncharged entities become ionized

Brønsted – Lowry

Acids – proton donor

Bases – proton acceptor

• explains that bases without OH- can exist

  • NH3

Matter?

• the stuff of the universe

• anything that has mass and takes up space

Dalton’s Atomic Theory

• was trying to explain chemical change

• 1. Matter is composed of tiny particles called atoms

• 2. atoms are indivisble

• 3. atoms cannot be created nor destroyed

• 4. atoms of an element are the exact same

• 5. atoms of different elements are different

• 6. chemical change is the union or seperation of atoms

• 7. atoms combine in simple whole number ratios

Discovery of Electrons

• Crooke’s discharge tube

• two metal places inside a sealed glass tube

• electricity was added

• stream of particles seem going from the anode → cathode

• must be negative

Discovery of Protons

• Goldstein

• Why were they neutral then?

  • = he made a cathodes ray tube

  • the electrons knocked out electrons from the gas

  • those pos charged particles flowed to the anode

  • made coloured light

  • = protons

Discovery of Radioactivity

• Becqurel

Thomson’s model

• plum pudding

• dough + raisins

Gold Foil Experiement

• Rutherford

• most particles passed trhough the foil

• some deflected at angled

• some refleced back!

• atom has a nuclues

• nuclues is postive

• nucleus is tiny

• atom is mostly empty space

Neutrons discovery

• Chadwick

• finds out neutrons exist to stablies the nucleus

Electron affinity

energy absorbed or released for the additon of an electorn

Electronegativiy

ability of an atom to attract electrons (covalent bonds)

Bohr Theory

• 1. In every H-atom there are only certain paths an electron can move

  • each path has definite fixed engery

• 2, these energy levels are orbits

• 3. electrons can travel in one orbt w/o losing energy

• 4. can jump up an energy level with added energy

he wrongly assumed u can assume the exact position of electrons

they don’tjump up in that way

only works for hydrogen

however he did help with the idea that electrons are organixed in the cartain way

Coloured lightfrom energized elements

• occurs because introducing energy can make the electron jump up an energy level but then fall back down and it released the enegrry as coloured light

ionic

• high melting points

• soluble in water

• conduct electricity in solution

• not soluble in organic solvents

Covalent

• low melting points

• not very soluble in h2o

• not good conductors

• soluble in organic compounds

Rate of reactions

• surface area

• temperature

• size

• particle contact

• catalysts