iGCSE Edexcel Chemistry Metallic Bonding & Electrolysis

half equation

the part of an overall reaction that represents, separately, either an oxidation or a reduction

anode

positive electrode, where oxidation occurs

cathode

negative electrode, where reduction occurs

electrode

electrical conductor

cation

a positively charged ion

anion

a negatively charged ion

electrolysis

a chemical change caused by passing an electric current through an ionic compound that is either molten or in solution

electron flow

anode to cathode

metallic bonding

electrostatic attraction between positive metal ions and delocalised electrons

delocalised electrons

outer electrons do not have fixed positions but move freely

malleable

capable of being shaped or bent

oxidation

loss of electrons

reduction

gain of electrons

electrostatic attraction

the attraction between positive and negative charges

electrolyte

a substance that breaks up into ions when it is dissolved in water

PANIC

positive anode negative is cathode

OIL RIG

oxidation is loss, reduction is gain

molten

melted

aqueous

dissolved in water

inert

inactive

ions in water

H⁺ and OH⁻

halide

a compound formed with a halogen

never have fear of ice cold beer

nitrogen, hydrogen, fluorine, oxygen, iodine, chlorine, bromine

halogen

group 7 elememts

alloy

a mixture of two or more metals

why are alloys harder than pure metals?

the different sized atoms of the metal, make it difficult for the layers to slide over each other

ductile

can be drawn into wires

rules for aqueous solutions

1. lower reactivity metals are discharged instead of H+ ions

2. halide ions are discharged instead of OH-

3. H+ ions are discharged instead of higher reactivity metals

4. OH- ions is discharged instead of sulfate, nitrate, carbonate, hydroxde

hydrogen ion

hydroxide ion

ammonium ion

carbonate ion

nitrate ion

sulfate

quantitative electrolysis

the amount of substance at an electrode is directly proportional to the quantity of electricity passed

if the litmus paper remains blue or red the solution is ...

neutral

if the red litmus paper remains red and blue litmus turns red the solution is ...

acidic

if red litmus paper turns blue and blue litmus paper remains blue the solution is ...

alkaline

what are electrodes made of?

graphite

acidic

pH less than 7

neutral

pH of 7

alkaline

having a pH greater than 7

why can't covalent compounds conduct electricity?

because there are no ions present to carry the charge

redox

reduction and oxidation

nonelectrolyte

has no freely moving ions when dissolved

OH- forms

oxygen

reactant

chemical substance that is present at the start of a chemical reaction

products

ending materials in a chemical reaction.