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Question 1

what is needed for:

alkene to alkane

Answer 1

H2, Nickel catalyst

Question 2

what is needed for:

alcohol to haloalkane

Answer 2

NaX e.g. (NaBr) and H2SO4.

?distil?

Question 3

what is needed for:

alcohol to alkene

Answer 3

heat, conc. H2SO4 or H3PO4

Question 4

what is needed for:

alkene to alcohol

Answer 4

steam hydration, H3PO4 catalyst

Question 5

what is needed for:

alkane to haloalkane

Answer 5

UV light

Question 6

what does bromine test for

Answer 6

presence of c=c

Question 7

average bond enthalpy

Answer 7

the enthalpy change when 1 mol of bonds of gaseous covalent bonds break

Question 8

stereoisomer

Answer 8

same structural formula but different arrangement of atoms in space

Question 9

3 ways polymers can be disposed of and detail

Answer 9

• buried- e.g. landfill= used for plastics that are difficult to separate
• reused- organic feedstock
• burned- this can generate electricity/ energy however wasteful products may be produced

Question 10

sigma bond

Answer 10

when 2 s orbitals overlap, they overlap in a straight line giving the highest possible density

Question 11

pi bond

Answer 11

sideways overlap of adjacent p orbitals

-sticks out above and below the nuclei- lower bond enthalpy

Question 12

heterolytic bond fission

Answer 12

-the bond breaks unevenly, one of the bonded atoms receives both electrons

Question 13

homolytic bond fission

Answer 13

-the bond breaks evenly and each atom receives 1 electron, forms free radicals

Question 14

why is each successive ionisation energy higher than the one b4

Answer 14

• as each electron is removed, there is less repulsion between the remaining electrons so each will be drawn closer to the nucleus

Question 15

Br2 in water and cyclohexane

Answer 15

both orange

Question 16

I2 in water and cyclohexane

Answer 16

water= brown
cyclohexane= purple

Question 17

3 reasons why one element has a higher 1st ionisation than another

Answer 17

• increased shielding
• increased atomic radii
• less nuclear attraction

Question 18

how is a pi bond formed

Answer 18

the sideways overlap of adjacent P orbitals

Question 19

chlorine atoms destroying the ozone:

Answer 19

cl2---> 2Cl.
Cl.+O3---> ClO. + O2
ClO. + O--> Cl. + O2
overall
O3 + O ---> 2O2