Chemistry Groups Redox Displacement reactions

Group 1

Alkali metals - very reactive, soft metals, low density, 1 outer electron, form +1 ions

Reducing agent

Loses electrons and is oxidised

Boiling point down a group..

Increases because atoms get bigger and intermolecular forces increase

Covalent bonding

A bond created by sharing of electrons between non-metals

Why do larger molecules have higher boiling points?

More electrons create stronger intermolecular forces

Group 1 properties

Soft can be cut with knife low melting points react vigorously with water

Group 1 + water

Forms metal hydroxide and hydrogen, exothermic reaction

Group 4

Carbon group - 4 outer electrons, can form 4 bonds

Group 5

Nitrogen group - 5 outer electrons, form -3 ions or 3 covalent bonds

Group 6

Oxygen group - 6 outer electrons, form -2 ions

Group 7

Halogens - very reactive, non-metals, diatomic, form -1 ions

Group 7 properties

Coloured toxic diatomic gases or liquids at low melting points

Group 7 + metals

Forms metal halide salts

Oxidation

Loss of electrons

Oxidising agent

Gains electrons and is reduced

Group 1 reactivity trend

Reactivity increases down the group due to increased distance and shielding from the positive nucleus

Shielding

Inner electrons reduce attraction to outer electrons as they "shield" them from the positive nucleus

Transition metals

High melting points, dense, less reactive, form coloured compounds

Transition metal catalysts

Speed up reactions without being used up

Why are transition metals less reactive?

Outer electrons are held more strongly by nucleus

Intermolecular forces

Weak attractions between molecules

When intermolecular forces increase, boiling point...

Increases, because stronger intermolecular forces give higher boiling points

Redox in displacement reactions

The more reactive metal is oxidised and the less reactive metal ion is reduced

Why are some elements diatomic? (H2 N2 O2 F2 Cl2 Br2 I2)

They exist as pairs of atoms to achieve a full outer shell through covalent bonds and become more stable (H2 N2 O2 F2 Cl2 Br2 I2)

Group 2

Alkaline earth metals - reactive metals, 2 outer electrons, form +2 ions

Group 2 properties

Denser than Group 1, higher melting points, less reactive

Group 2 + water

Forms metal hydroxide and hydrogen, slower reaction than Group 1

Group 3

Boron group - 3 outer electrons, form +3 ions

Group 0

Noble gases - full outer shell, very unreactive, gases, low boiling points

Displacement reaction

When a more reactive element replaces a less reactive one in a compound

Metal displacement Zn + CuSO4 →

Zn + CuSO4 → ZnSO4 + Cu

Halogen displacement

When a more reactive halogen displaces a less reactive one (eg. Chlorine displaces bromine)

Reactivity series

List of metals ordered by how easily they lose electrons

Reduction

Gain of electrons

OIL RIG

Oxidation Is Loss, Reduction Is Gain

Redox reaction

Oxidation and reduction occur together within a reaction

Group 7 reactivity trend

Reactivity decreases down the group due to weaker attraction of outer electrons to the positive nucleus

Ionic bonding

Electron transfer between metal and non-metal forming oppositely charged ions