| A | B |
|---|
| a hydrocarbon contains | carbon and hydrogen only |
| a saturated hydrocarbon | contains only single bonds |
| an unsaturated hydrocarbon | a C=C double bond |
| alkanes are ............... hydrocarbons | unsaturated |
| alkanes are ........ hydrocarbons | saturated |
| CH4 is | methane |
| C2H6 is | ethane |
| C3H8 is | propane |
| C4H10 is | butane |
| C2H4 is | ethene |
| C3H6 is | propene |
| C4H8 is | butene |
| There are two different compounds with the molecular formula C4H8; they are described as | isomers |
| the two isomers of C4H8 are | CH3.CH=CH.CH3 and CH3.CH2.CH=CH2 |
| an alkene ........Br2(aq) | readily decolourises |
| with Br2 and an alkene an ............. reaction occurs | electrophilic addition |
| C2H4 + Br2 ---> | CH2Br.CH2Br |
| CH2Br.CH2Br is called | 1,2 dibromoethane |
| C2H4 + H2 ---> | C2H6 |
| C2H4 + H2 --->C2H6 needs Ni; it's a | catalyst |
| C2H4 + HBr ---> | CH3.CH2Br |
| CH3.CH2Br called | bromoethane |
| C2H4 + Cl2 ---> | CH2Cl.CH2Cl |
| CH2Cl.CH2Cl called | 1,2 dichlorethane |
| CH3.CH=CH2 + HBr ---> | CH3.CHBr.CH3 |
| When a reactant like HBr is added to unsymmetrical alkene the (-) part of the reactant | bonds to the C with less H |
| CH3.CH2.CH=CH2 + HBr ---> | CH3.CH2.CHBr.CH3 |
| CH3.CH2.CHBr.CH3 called | 2-bromobutane |
| CH2=ch2 + potassium manganate-VII (purple) | turns purple to colourless |
| all hydrocarbons burn in air and form | CO2 & H2O |
| CH4 + Cl2 --> CH3Cl + ...... | HCl |
| CH4 + Cl2 --> CH3Cl + HCl is a .... reaction | substitution reaction |
| CH4 + Cl2 --> CH3Cl + HCl conditions | bright sunlight or ultra violet |
| CH4 + Cl2 --> CH3Cl + HCl mechanism involves | free radicals |
| CH4& Cl2 first stage of mechanism is | Cl-Cl ---> 2Cl* |
| Cl-Cl ---> 2Cl* called ......stage | initiation |
| CH4 + Cl* --> | CH3* + HCl |
| CH4 + Cl* --> CH3* + HCl called .........stage | propagation |
| CH3* + Cl* --> CH3Cl called ......stage | termination |
| CH3Cl called... | chlormethane |
| CH4 + Br2 --> | CH3Br + HBr |
| CH3.CH2.CH3 + Br2 --> | CH3.CH2.CH2Br + HBr |
| CH3.CH2.CH2Br called | 1-bromopropane |
| C3H8 used as a | camping gas |
| C3H8 needs to be stored in | pressurised containers |
| C8H18 present in | petrol |
| advantage of C8H18 over C3H8 | does not need a pressurised container for storage |
| The alkane with 20 C atoms ; molecular formula is | C20H42 |
| Alkene with 16 C atoms - molecular formula is | C16H32 |
| General formula for alkanes is | CnH2n+2 |
| General formula for alkenes is | CnH2n |
