Unit 1 Test

Solution

solute dissolved in solvent

Salt dissolved in water

Attraction between water + sodium and water + chloride is stronger than sodium + chloride

Endothermic

Separates molecules

Exothermic

Joins molecules

Why do solids conduct

Ion movement → ion collisions that carry charge

Level of conductivity

Determined by number of ions and collisions

Iodine in water

Iodine’s temporary dipole forms induced dipole bond with water

Iodine in water hexane added

Hexane and iodine more attracted to each other

Why do particles form solids

Kinetic energy and temperature

Ionic solids

Electrostatic attraction

Molecular solids

LDF, dipole-dipole, H-bonds

Metallic solids

Positive ions surrounded by a sea of electrons, metallic bond

Covalent network

Covalent bonds

Graphite

Conducts in horizontal planes and is a lubricant

Acid

Proton donor

Base

Proton acceptor

Ph scale

Increment in one pH is 10x H+/OH-

Strong acids

H2SO4, HI, HBr, HNO3, NCl, HClO4

Strong bases

First two columns on table

Neutralization

Acid and base react to form a salt and water, moles H+ = moles OH-

Incomplete neutralization

Moles of H+ or OH- left over

Oxidation

Electron removed

Reduction

Electron added

Half reaction

Oxidation or reduction

Oxidizing agent

Gets reduced

Reducing agent

Gets oxidized

Oxidation numbers rules

Alkali metals: +2, Alkaline metals: +2, Oxygen: usually -2 but -1 in peroxides, Hydrogen: +1 with nonmetals and -1 with metals, Fluoride: always -1

Spontaneous

Strong oxidizing + strong reducing, energetically favourable

Standard cell potential

Let’s us compare reactions

Non-spontaneous

Weak oxidizing + weak reducing, not energetically favourable

Potential difference

Energy delivered by the movement of electrons

Volt

Energy carried by a coulomb of electrons

Ampere

Number of coulombs that travel per second

Coulomb

A bunch of electrons

Electrode

Conductor where half reaction occurs

Anode

ELectrode where oxidation takes place

Cathode

Electrode where reduction takes place

Solutions used

Usually nitrate b/c they dont react

Salt bridge

Allows the movement of ions and balances the charges