Acid and bases Flashcards
Weak acid
Slightly dissociates into its ions
E.g. Ethanoic acid
Carbonic acid
Strong acid
Fully dissociates into its ions
E.g. Hydrochloric acid
Nitric acid
Sulfuric acid
Salt
When a metal ion has replaced the H+ in an acid
Strong bases
The oxides or hydroxides of group 1+2 metals
E.g. Sodium oxide
sodium hydroxide
Magnesium oxide
Weak base
Ammonia
Alkali
Base that dissolves in water
Characteristic reaction of acids
Acid + Base -> salt + water
Acid + Metal -> salt + hydrogen gas
Acid + carbonate/ hydrogen carbonate -> salt + water + carbon dioxide gas
Basicity of acids
Number of replaceable hydrogens in the acid
Monobasic - 1 replaced
dibasic -2 replaced
Arrhenius theory
Acid in water produces H+ (hydrogen ions)
Base in water produces OH- (hydroxyl ions)
Brønsted-Lowry Theory
Acid is a proton donor
Base is a proton acceptor
Conjugate acid-base pair
Acid+base that differ by a proton
Prefixes
1 - meth
2 - eth
3 - prop
4 - but
5 - pent
6 - hex
7 - hept
8 - oct
9 - non
10 - dec
Hydrocarbons
Molecules that contain carbon + hydrogen atoms only
Homologus theory
A group of molecules with the same functional group:
Have similar chemical properties
Have a gradual change in physical properties with increasing chain length
Have successive members differ by CH3 + CH2
Have the same general formula
Have similar methods of preparations
alkanes
All C to C bonds are single bonds
alkenes
At least 1 C to C bonds are double bond
Alkynes
At least 1 C to C bonds are triple bonds
alcohol
At least one C-O-H
Allotrope
Different physical forms of all the same element
Octane number
A measure of how much a fuel resist knocking
knocking
Sound an engine makes when the fuel in the cylinder is not ignited at the correct time
Hydrocarbons with long chain
short chains
branching
have ring in their structure
Catalytic cracking
A chemical technique where less useful long chain hydrocarbons are heated in the presence of a catalyst to form shorter more useful molecules including alkenes
Isomers
Isomers are compounds with the same molecular formula but different formulas
Isomerisation
Heating a hydrocarbon in the presence of a catalyst form a branched isomer with a higher octane number
Dehydrocyclisation/recycling
A process where a straight hydrocarbon is converted into a cyclic hydrocarbon with a higher octane number + H2
Oxygenates
increase octane number
makes fuel burn cleaner thus reducing harmful emissions
rich in oxygen
Methyl - tert -butyl - ether (MTBE)
Crude oil being heated
Refinery gas - fuel
Petrol - Cars
Naphtha - Make chemicals
Kerosene - Jet fuel
Diesel - For diesel engines
Lubricating oil - Oil for car and other machines
Fuel oil - Fuel for ships and factories
