Inorganic Chemistry

Nonmetals

Elements

• Three main groups:

Metals:

• Group I-IV and the d-block
• 1,2,3 electrons on the outer shell
• Most of them is solid at room temperature (except mercury)
• Shiny grey (gold: yellow, copper: reddish brown)
• Conduct electricity and heat
• Malleable and ductile

Nonmetals:

• Group IV – VIII (plus Hydrogen)
• 4,5,6,7,8 electrons on the outer shell (Hydrogen: 1, Helium: 2)
• Gas (hydrogen, oxygen, nitrogen, chlorine)
• Liquid (bromine)
• Solid (carbon, sulphur, phosphor)
• Different colours
• Opaque or transparent
• Fragile
• Don’t conduct electricity and heat (insulators)

Metalloids

• They have metallic and nonmetallic properties

Nonmetals

Noble gases

• Group VIII: helium, neon, argon, krypton, xenon, radon

Structure:

They are made of individual atoms: closed outer shells

Physical properties:

• Colourless, odorless gases
• They aren’t soluble in water
• They don’t conduct electricity

Chemical properties:

• Noble gas notation: they have closed outer shell
• Nonreactive substances: don’t form chemical bonds and compounds

Presence, occurence:

• In the air (atmosphere)
• In rocks
• In crude oil and natural gas
• In stars

Use:

• He: filling airships, balloons
• He: artificial air (divers)
• Ne: „neon lights”
• Ar: protective gas in welding
• Kr: light bulbs
• Rn: radioactive (danger of cancer, rock dating)

Hydrogen

Structure

• Atom: 1 proton, 1 electron
• Molecule: H – H, H₂ (covalent bonding)

Physical properties

• Odorless, colourless gas
• Insoluble in water
• Density is the smallest (14,5 times lighter than the air)

Chemical properties

• Oxidation:
• 2H₂ + O₂ = 2H₂O, faint blue flame
• Mixture of hydrogen and oxygen (2:1): explosive gas
• Reaction with chlorine:
• H₂ + Cl₂ = 2HCl
• Reaction with copper oxide:
• CuO (black) + H₂ = Cu (red) + H₂O
• H₂ is reducing agent

Occurrence

• Volcanic gases
• Upper atmosphere
• In compounds (water, natural gas, crude oil, organic compounds)

Production

• Electrolysis of water

Use

• Production of ammonia, ammonium nitrate (fertilizer)
• Welding

Group VII: Halogens

• Name: „salt-makers”
• Fluorine (F): pale yellow gas
• Chlorine (Cl): yellow-green gas
• Bromine (Br): orange-brown liquid
• Iodine (I): grey crystals

Structure:

• Outer shell: 7 electrons
• In nature: diatomic molecules, covalent bonding: F₂, Cl₂, Br₂, I₂
• Nonpolar molecules

Chlorine

Physical properties:

• Yellow-green gas
• Distinctive odor (makes cough)

Chemical properties:

• Diatomic molecules
• Reactive
• Poisonous
• Reaction with water:
• Cl₂ + H₂O = HCl (hidrochloric acid) + HOCl (bleach)
• Bleach: decolorises
• Reaction with hydrogen:
• H₂ + Cl₂ = 2HCl
• Reaction with sodium:
• 2Na + Cl₂ = 2NaCl  redoxireaction

Occurence: in volcanic gases, in compounds

Importance:

• Poisonous, disinfectant,
• Industry: hydrochloric acid, pesticides, pharmaceutical industry

Iodine

Grey, solid crystals, vapour is violet

Solubility:

• Slightly soluble in water
• Soluble in alcohol (brown solution) oil, gasoline (pink solution)

Sublimation: solid transforms to gas without liquid state

Importance: disinfectant

Hydrogen chloride

Structure:

• H-Cl
• Electronegativity: H: 2.1, Cl: 3.0
• Cl attracts the bonding electrons much more: polar bond, dipole molecule

Physical properties:

• Colourless gas
• Distinctive odor (makes cough)
• Soluble in water: forms hydrochloric acid
• :
• HCl + H₂O = H₃O⁺ + Cl^-      (acidic pH)
• Hydronium ion and chloride ion is formed

Chemical reactions

• Reacts with metals (except copper), hydrogen and salts are formed:
• 2HCl + Zn = ZnCl₂ + H₂
• 6HCl + 2Al = 3AlCl₃ + 2H₂

Occurence

• Volcanic gases
• Stomach

Production:

• H₂ + Cl₂ = 2HCl

Use:

• Cleaning
• Textile, paint and pharmaceutical industry