1. Carboxylic Acids
1.1. physical properties
1.1.1. simple carboxylic acids have sharp or unpleasant odours.
1.1.2. lower molecular mass
1.1.3. Boiling points
1.1.3.1. Boiling points higher than alkanes
1.1.3.2. same number of carbon atoms than alkanes
1.1.3.3. Much energy is required to overcome the stronger force of attractions between the larger carboxylic acid molecules.
1.1.3.4. the boiling points increase with increasing number of carbon atoms per molecule.
1.1.3.5. room temperature
1.1.3.5.1. colourless liquids
1.1.3.5.2. have 10 or more carbons are wax-like solids.
1.1.3.5.3. are liquids at room condition
1.1.4. Solubility:
1.1.4.1. • Up to four carbon atoms are very soluble in water • due to water molecules being strongly attracted to the -COOH group.
1.1.4.2. •solubility decreases with increasing number of carbon atoms per acid molecule. •The longer carboxylic acid molecules are insoluble in water.
2. Alcohol
2.1. physical properties
2.1.1. Simple alcohols
2.1.1.1. very soluble (infinite solubility) in water
2.1.2. enthanol
2.1.2.1. (a)liquid at room conditions
2.1.2.2. (b) colourless
2.1.2.3. (c) sharp smell
2.1.2.4. (d) completely miscible 混溶 with water
2.1.2.5. (e) low boiling point (78 °C)
2.1.2.6. (f) highly volatile
3. Overview
3.1. Carbon compounds
3.1.1. def: compounds that contain carbon elements.
3.1.2. 组成: These compounds contain carbon and hydrogen / carbon and hydrogen together with other elements such as oxygen, sulphur, nitrogen, halogens and phosphorus.
3.1.3. groups
3.1.3.1. organic compound
3.1.3.1.1. def: compounds containing carbon atoms
3.1.3.2. inorganic compound
3.1.3.2.1. def：all compounds don't contain carbon
4. Alkane
4.1. physical properties (Alkane & Alkene & Alkynes)
4.1.1. covelent compounds 共价键: • held together by weak intermolecular forces 分子间作用力
4.1.2. electrical conductivity: • cannot conduct electricity
4.1.2.1. •They are covalent molecules. •They consist as neutral molecules. •The absence of mobile移动 ions makes them unable to conduct electricity.
4.1.3. Melting point and boiling point: • low melting point and boiling point
4.1.3.1. • However the melting points and boiling points will gradual increase • As the number of carbon atoms per molecule increases, the molecule size gets bigger and the intermolecular force grows stronger. • More energy is needed to overcome the stronger intermolecular forces of attraction between the molecules. • Hence, the melting points and boiling points of the alkenes increase with increasing number of carbon atoms per molecule.
4.1.3.2. generally they have low melting points and boiling points. This is because the molecules are held together byweak intermolecular forces whichrequire small amount of energy to overcome.
4.1.3.3. • intermolecular foreces: alkyne > alkane & alkene • As alkyne has less volatile
4.1.3.4. at room condition:
4.1.3.4.1. Alkane gas: 1 - 4 carbon atoms liqiud: 5 - 17 carbon atoms solid: more than 17 carbon atoms
4.1.3.4.2. Alkene gas: 2 - 4 carbon atoms liqiud: 5 - 7 carbon atoms (more than 5 are liqiud / solid)
4.1.3.4.3. Alkyne gas: 2 - 4 carbon atoms liqiud: 5 - 7 carbon atoms (more than 5 are liqiud / solid)
4.1.4. Solubility: • obeys "like dissolve like" rule: dissolve in organic solvents; insoluble in water
4.1.4.1. organic solvent eg. • ether / Ethoxyethane / Diethyl C2H5OC2H5 • benzene C6H6 • tetrachloromethane CCl4
4.1.5. Density:
4.1.5.1. less dense
4.1.5.1.1. Alkane less dense than water (1.0 gcm^-3)
4.1.5.1.2. Alkene Liquid & gas: less dense than water
4.1.5.2. liquid: form colourless oily layer floating on top of the water
4.1.5.3. number of carbon atoms in molecules / density increase, alkane molecules bigger, alkane molecular masses increased.