chem unit 2

Alkali metals

Six chemical elements in Group 1 of the periodic table that are very soft and highly reactive.

Allotrope

Different structural modifications on forms of the same chemical element existing in the same physical state.

Catalyst

A substance that reduces activation energy to speed up a chemical reaction

Catalytic converter

A emission controls device in a vehicle’s exhaust system that transforms toxic engine pollutants into less harmful gases before they leave the tailpipe.

Chromatography

A laboratory technique that is used the separate the polarities of components in different mixtures.

Earth Metals

6 chemical elements in Group 2 of the periodic table that are shiny, reactive, and silvery-white.

Emission Spectra

Sets of wavelengths emitted by an element

Endothermic

Process that involves more bonds forming than breaking in the target system, resulting in the absorption of thermal energy from the surroundings.

Exothermic

Process that involves more bonds breaking than forming in the target system, resulting in the increase of thermal energy in the surroundings.

Fossil Fuel

Non-renewable substances from animals buried millions of years ago that are burned off for industrial purposes, releasing CO2

Nanomaterial

Particles between 1-100 nanometers (nm) in size

Net ionic equation

A chemical equation that shows only the specific particles, ions, and molecules that actively participate in a chemical reaction.

Saturated

Mixture that has dissolved the maximum amount of solute that it can normally hold at it’s given temperature

Supersaturated

Solution that holds more dissolved solute than the maximum amount that it can normally dissolve in that solvent at a given temperature.

Unsaturated

Solution that has less dissolved solute than the maximum amount it can possibly hold at it’s given temperature.

Typical Mixture separated by Electrostatic Attraction

Mixture of electrostatic and non-electrostatic materials

Property used by Electrostatic Attraction

Difference in electrical charge

Typical Mixture separated by Filtration

Mixture of insoluble solid and liquid

Property used by Filtration

Difference in state and size of particles

Typical Mixture separated by Fractional distillation

Mixture of liquids

Property used by Fractional distillation

Significant but small difference in boiling points

Typical Mixture separated by Magnetic separation

Mixture of magnetic and non-magnetic material

Property used by Magnetic separation

Difference in attraction to a magnetic field

Typical Mixture separated by Sieving

Mixture of solids or solids and liquids

Property used by Sieving

Difference in particle size

Typical Mixture separated by Simple distillation

Mixture of liquids or solids and liquids

Property used by Simple distillation

Big difference in boiling points

Typical Mixture separated by Vaporisation/Evaporation/Boiling

Solution containing dissolved solids

Property used by Vaporisation/Evaporation/Boiling

Liquid has a much lower boiling point than dissolved solid

Typical Mixture separated by Separating funnel

Mixture of immiscible (undissolved) liquids

Property used by Separating funnel

Difference in densities

Atomic Radius

The total distance from an atom’s electrons to the outermost orbital of electron.

Atomic Radius trends

Increases from left to right of a period

Increases down a group

First Ionisation Energy

Energy required by another atom to discharge an atom’s first electron.

First Ionisation Energy trend

Increases from left to right of a period.

Decreases as you go down a group

Electronegativity

The ability of an atom to attract electrons towards itself.

Electronegativity Trend

Increases from left to right down a period

Decreases as you go down a group

Full valence shell: 0 Electronegativity

Formation of flame colours

When we give the electrons lots of energy (excitation), they move to a new energy level. When electrons lose this energy, they fall back into their original level (de-excitations). The loss of energy is in the form of light (photons) - the different lights we see comes from these different atoms.

Sodium Chloride colour

Bright-yellow orange

Barium Chloride colour

Yellow-green

Strontium Chloride colour

Bright Red/Scarlett

Metallic Bonding electron location

Sea of delocalised electrons

Covalent Bonding electron location

Shared between atoms

Ionic bonding electron location

Transferred to the anion

Metallic bonding type of atoms

Metal atoms

Covalent bonding type of atoms

Non-metal atoms

Ionic bonding type of atoms

a Metal and a non-metal

Metallic bonding electrostatic attractions between

Metallic cations vs delocalised electrons

Covalent bonding electrostatic attractions between

Positive nuclei and the shared pair/s of electrons

Ionic bonding electrostatic attractions between

Metallic cations vs non-metallic anions

Metallic bonding conductivity

Conductive

Covalent bonding conductivity

Not Conductive

Ionic bonding conductivity

Only conductive when dissolved or molten

Is Metallic bonding malleable or ductile in solid?

Yes.

Metals exist as a sea of delocalised electrons surrounding positive metal cations. This bonding is non-directional. When a force is applied the iron can change shape without disrupting the bonding.

Yes.

Metals exist as a sea of delocalised electrons surrounding positive metal cations. This bonding is non-directional. When a force is applied the iron can change shape without disrupting the bonding.

Is Metallic bonding malleable or ductile in solid?

Is Covalent bonding malleable or ductile in solid?

No.

Covalent molecules are held by their weak intermolecular forces, and strong and directional intramolecular forces. This makes the compounds to be soft and easy to break (IMF breaking).

No.

Covalent molecules are held by their weak intermolecular forces, and strong and directional intramolecular forces. This makes the compounds to be soft and easy to break (IMF breaking).

Is Covalent bonding malleable or ductile in solid?

Is Ionic bonding malleable or ductile in solid?

No.

Ionic compounds are composed of cations and anions in a rigid 3D lattice. When a force is applied, the like charges align and repel, causing the substance to shatter.

No.

Ionic compounds are composed of cations and anions in a rigid 3D lattice. When a force is applied, the like charges align and repel, causing the substance to shatter.

Is Ionic bonding malleable or ductile in solid?

Similarities between covalent molecular and covalent network

• Involvement of Covalent Bonds

• Generally are Electrical Insulators

• Composed of Non-Metals

• No Free Ions

differences between covalent molecular and covalent network

• Structure

• Bonding

• Melting/Boiling Points

• Hardness

• Conductivity

Polar

• Asymmetrical

• Atoms with different electronegativities bonded to the central atom

• Can contain lone pairs of electrons

• One end of the molecule is slightly positive while the other is slightly negative

• e.g. HF, HCl, NH3, CH3Cl

Non-Polar

• Symmetrical

• All sides around the central atom are identical

• No unshared pair of electrons

• e.g. CCl4 - Tetrahedral, BF3 - Trigonal Planar

Steric Number 2, Zero Lone pairs

Linear

Steric Number 3, Zero Lone Pairs

Trigonal Planar

Steric Number 3, One Lone Pair

Bent

Steric Number 4, Zero Lone Pairs

Tetrahedral

Steric Number 4, One Lone Pair

Trigonal Pyramidal

Steric Number 4, Two Lone Pairs

Bent

Alkane Substitution reaction requirement

UV Light

Alkane Substitution reaction example equation

UV(Cl₂ + CH₄) → CCl₄ + HCl

Alkene Hydration Example equation

CH₂CH₂ + H₂0 → CH₃CH₂OH

Alkene Halogenation Example equation

CH₃CHCH₂ + Br₂ → CH₃CHBrCH₂Br

Alkene Hydrohalogenation example equation

CH₂CH₂ + HBr → CH₃CH₂Br

Benzene Substitution requirement for reaction

Presence of a Catalyst

Benzene Substitution example equation

FeCl₃(C₆H₆ + Cl₂) → C₆H₅Cl + HCl