Chem EOYT

Brownian motion

the random motion of particles

diffusion

particles mix and spread by colliding with other moving particles and bouncing off each other in all directions

atom

the smallest particles, cannot be broken down further

molecule

2 or more atoms bonded together

ions

atoms or molecules with a charge (+ or -)

How does particle in a solid move

the particles are arranged in a lattice. Particles cannot move they only vibrate in place

How does particle in the liquid move

the particles can move and slide past each other. Particles are still close together but not fixed

How does particles in gas move

the particles are very far apart and move quickly. The particles collide with each other and bounce off in all directions

Melting

when a solid is heated to make the particles expand and turn liquid

Boiling

when a liquid is heat and the particles bump into each other and start breaking away to form gas

Evaporating

some particles in a liquid have enough energy to form gas even below the boiling point

What is atom made of

atoms consist of nucleus and a cloud of electrons surrounding it

the nucleus consists of protons and neutrons

protons: positive electrons: negative neutrons: neutral

How can we identify an atom

number of protons (atomic number )

Charges of atom

Atom has no charge. It has equal amount of protons and electrons

the total number of protons + neutrons in an atom is its nucleon number

Isotopes

Isotopes are atoms that have the same protons number (same element), but a different nucleon number

How are electrons arranged

Electrons are arranged in shells around the nucleus

• the shells get more energy as they are added

The first shell: 2 second shell: 8 third shell: 8

What are electrons in outer shell called

valency electrons

Compound

A compound is made of atoms of different elements bonded together - described by a formula

Mixture

a mixture contains different substances that are not chemically bonded together

What are signs of chemical change

1. one or more chemical substances are formed

   iron + sulfur → iron(II) Sulfide

2. energy is taken or given during the reaction

3. the change is usually difficult to reverse

ion

a charged particle because it has an uneven number of protons and electrons

ionic bond

the bond that forms between ions of opposite charges

non metal and metal reaction

a metal reacts with a non metal to form an ionic compound

metals form positive ions (lose electrons)

non metal form negative ions (gain electrons)

Covalent bonds

when 2 non metals react, both need to gain electrons so they share

both nuclei attract the electrons → covalent bond

a single covalent bond is formed when atoms share 2 electrons (1 pair)

what is molecule bonded with

a molecule is a group of atoms bonded covalently

ionic compounds properties

high melting and boiling points

usually soluble in water → dissolved into ions

conduct electricity, when melted or dissolved in water

when dissolved, charged particles are free to move

covalent compounds properties

low melting and boiling point

many covalent liquids are volatile (evaporate easily)

insoluble in water

can dissolve in some other solvents

do not conduct electricity

Giant covalent structure

Giant covalent structures (macromolecules) are strong structures with very high melting and boiling points

metallic bonds

bonds held together by the strong attraction to the free electrons between them

metals properties

metals have high melting points

they are malleable (shapable) and ductile (can be drawn into wires)

Because the large can slide without breaking

good conducts of heat and electricity

because the sea of delocalized electrons

What are the solids that can conduct electricity

The only solid that conduct electricity are metals and graphite

can molecular substances conduct electricity

No

can ionic structure conduct electricity

only when melted or dissolved in water → they break down

electrons is the breaking down of an ionic compounds, when melted or in aqueous solution, by the passage of electricity

Solute

substance that dissolves

solvent

liquid that dissolves the solute

Solution

solute + solvent

Limiting reactant

the substances that reacts fully

surplus

the substance that is left over after a chemical reaction

dilution

reducing the concentration of a solution by adding more solvent

Acids properties

• turn blue litmus blue

• pH under 7

• when dissociated in water, the solutions contain hydrogen ions

Bases

• turn red litmus paper blue

• bases that are soluble in water are alkali

• alkali dissociate in water, the solution contains hydroxide ions

Acids solutions

in solutions of strong acids, all the molecules dissociate in water

in solutions of weak acids, only a few molecules dissociate

the higher the concentration of hydrogen ions, the lower the pH

Base solutions

strong bases dissociate completely into hydroxide ions

weak bases dissociate partially into hydroxide ions

the higher the concentration of hydroxide ions, the higher the pH

Are acids proton donners?

Yes

Are base proton acceptors?

yes

True or false,
strong acids and bases conduct electricity better

Yes, because fully ionized

Ammonia + water =?

ammonia is a weak base and produces OH- by reacting with water, even though water is not acidic, it donates a proton (H+) to ammonia

Acid reactions

acid + metal → salt + hydrogen

acid + base → salt + water

acid + carbonate → salt + water + CO2

Whats a neutralization

if water and salt are produced in a reaction

during neutralization, H+ ions combine with OH- ions to form water

ionic equation

shows just the ions that take part in the reaction

The names of organic compound

families and how many carbon atoms are in them

functional groups

a functional group is a specific group of atoms that give the molecule its chemical properties and reactivity

prefixes

meth-1 eth-2 prop-3 pent-5 hex-6 hept-7

homologous series is a family

when all compounds fit the same general formula

what are alkanes, alkenes, alcohol, carboxylic acids?

• alkanes - CnH2n+2

• alkenes - CnH2n

• alcohol - CnH2n+1OH

• carboxylic acids - CnH2nO2 or CnH2n+1COOH

Alkanes

they are hydrocarbons - they contain only carbon and hydrogen

True or false

there carbon are not single bond

false, they are all single bonds

What are they found in

found in petroleum and natural gas → methane, ethane etc.

What states of matter are alkanes.

first 4 alkanes are gases at room temp. next 12 are liquid and rest are solids

Are they saturated?

Yes → only single bonds → un-reactive

Are they flammable?

flammable → used as fuels → with O2

they go through incomplete combustion when there isn’t enough O2

Alkenes

unsaturated → double bond → more reactive

How are they formed

formed from alkanes by cracking

ethene + water → ?

ethanol

addition reaction: turns unsaturated alkane to a saturated compound

Alcohols

contain OH functional group

the number in the name tells where the OH is

Carboxylic acids

ethanore acid - main acid from this group

reacts with metals and bases to form salts