Chemistry

Random facts

Cryolite is used in extracting Al in AlO by electrolysis

• high melting point

• high conductivity

Activation Energy

Minimum energy needed for colliding particles to react

Iron rusting

• water

• oxygen

Fuel Cell

• product water ONLY

• no carbon emission

• difficult + dangerous to store/move

Reversible reaction

Reaction where reactant reacts to form product and the products can react to form the reactant.

Transition Elements

• High melting point

• High density

Equilibrium

The forward and backward reaction is equal.
(P+R conc. same)

Chlorine Gas

Pale green yellow gas

Oxygen Gas

Colorless

Copper

Pink/brown

Metallic bond

• metal + non-metal

• strong electrostatic attraction between + and - ions

• high BP+MP

• loose “e“ = free moving “e“ = conductivity

Electrolysis

The decomposition of metals in molten/aq solution compound into elements when in m/aq solution using electricity

(ion to atom)

Ductile

Pulled into wires

Malleable

Hammered into diff shape

Isotopes

• same no of P

• diff neutron

Allotropes

• diff structural form

• same element

Pipette

• accurate

• fixed volume

Separating Funnel

Separate immiscible liquid

G7

• monoatomic

• full shell

BP + MP

no range

Harbor Process (Ammonia)

• 450 degree,200 atm,20 000 KPA

• closed system
  (cuz H+N recycled)

• iron catalyst

Contact Process (Sulfuric Acid)

• 450 degree, 2 atm, 20 KPA

• closed system (sulfuric trioxide remove)

• vanadium (V) oxide

Uses of electrolysis

• extraction of metal

• electroplating
  (coat object with a thin film of metal using electrolysis)

Exothermic

• increase temp of surroundings

• BF>BB

• (-)

Endothermic

• decrease temperature of surroundings

• BB>BF

• (+)

Increasing temperature

favors endothermic reaction

Decreasing temperature

favors exothermic reaction

Increasing pressure

favors less molecules

Adding catalyst

increase rate of reaction but doesn’t affect position of equilibrium so doesn’t affect yield

Group number

Number or electron on the outermost shell

Period number

Number of electron shell

Platinum + Graphite

Inert electrode

Lubricant (Carbon) / Cutting tools

Giant Covalent structure

Barium Sulfate

Insoluble

Group 1

• Low melting + boiling point

• react with cold water = H gas

• heated with O2= white solid

Test for ammonia

Damp red litmus paper turn blue

Produce insoluble salts

soluble + soluble

test sulfur dioxide

test: acidified aqueous potassium manganate (VII)

observation : purple to colourless w

if use catalyst

lower activation energy Ea

Give alternative pathway