alkanes

Question 1

what is homologus series?

Answer 1

A homologous series as group of compounds:
1)general formula(CH2 is difference between one member by next)(CnH2n+2)

2)same functional grp ( same chemical properties undergoing same chemical reactions)

3)shows a gradation in physical properties(bp,mp) with increasing molecular mass and size

Question 2

what are Alkanes ?

Answer 2

Alkanes have general formula of CnH2n+2 and it does not have a functional group
#### have c-c single bond so they are saturated #####
They are unreactive and undergo similar chemical reactions:

chemical reactions:
— combustion
—-substitution
—- cracking

they are insolube in water

Question 3

name the 10 alkanes ?

Answer 3

1)methane
2)ethane
3)propane
4)butane
5)pentane
6)Hexane
7)heptane
8)octane
9)Nonane
10)Decane

Question 4

describe substitution reaction

Answer 4

It involves H atome being replaced by halogen atome(cl)
in pressence of UV light to form halogenoalkane and hydrogen halide(eg.HCL)

Question 5

what is cracking

Answer 5

cracking is the process of long-chain alkane into short-chain alkane and hygrogen/short-chain alkanes and short-chain alkanes

                       -1 atm
         -Al2O3 and SiO2 catalysts

Question 6

how is cracking used

Answer 6

1)short-chain alkane can meet the supply of car fuels
2)short-chain alkane-important for making plastics via addition polymersiation
3)H2 for manufacturing of margarine;or in the haber process

Question 7

importance of short-chain alkane

Answer 7

Smaller hydrocarbons has lower molecular mass and size,so less thermal engery to overcome the weak intermolecular forces of attraction ,so lower boiling point.Lower boiling point likely to evaporate so more volatile,vapoura present,surface area exposed for reactants to collide so more likely to burncompletely in combustion so more demand for fuel

Question 8

addition Polymerisation

Answer 8

it is just adding alkenes at high temp and high pressure with cataylst

Draw the equation of addition polymerisation butene,draw the monomer,polymer,repeat unit

Question 9

what is ethandioic acid +ethondial ?

Answer 9

ploy(ethy enthoante) +2n h2o

draw it and respresent it

if you are cinfused watch the video below
https://www.youtube.com/watch?v=U-eCXeFwTgY&t=28s

Question 10

Advantage of addition polymerisation and condensation polymerisation?

Answer 10

addition polymerisation proudce plastic which are non-biodegradeabe so it may land ,water and air pollution

condensation polymerisation produce biogradeable so it is good for the environment