Draw 2 repeat units of the addition polymer, poly(propene).
Category: Pure Chemistry
List the conditions for esterification.
- Gentle warming
- Catalyst: a few drops of concentrated sulfuric acid
List the conditions for fermentation of glucose solution.
- Temp 37 deg C
- Absence of oxygen
- Biological enzyme: yeast
List the conditions for hydration of alkenes.
- Temp 300 deg C
- Pressure 60 atm
- Catalyst: Phosphoric(V) acid, H3PO4
List the conditions for hydrogenation of alkenes.
- Temp 200 deg C
- Catalyst: nickel
List the conditions for substitution reaction of alkanes.
Presence of UV light.
List the conditions for catalytic cracking of long chain alkanes.
- Temp 600 deg C
- Catalyst: aluminium oxide or silicon (IV) oxide
Write down the general formula for: alkanes, alkenes, alcohols, carboxylic acids.
Alkane: CnH2n+2
Alkene: CnH2n
Alcohol: CnH2n+1OH
Carboxylic acid: CnH2n+1COOH
List the percentage composition of air.
- Nitrogen (78%)
- Oxygen (21%)
- Carbon dioxide (0.03%)
- Noble gases (less than 1%, mainly argon)
- Water vapour (variable)
Explain, using structure and bonding, why silicon dioxide has high melting and boiling point.
Silicon dioxide has a giant molecular structure, consisting of a large number of silicon and oxygen atoms covalently bonded to form a big tetrahedral structure. A lot of energy is needed to break the strong covalent bonds, resulting in the high melting point and boiling point of silicon dioxide.