ALKENES MS. 1. H 2 1 Ni/Pt/Pd (catalyst) 1 [2] 2. (i) decolourises 1 (ii)

Size: px

Start display at page:

Download "ALKENES MS. 1. H 2 1 Ni/Pt/Pd (catalyst) 1 [2] 2. (i) decolourises 1 (ii)"

Sherilyn Parrish
6 years ago
Views:

1 ALKENES MS. Ni/Pt/Pd (catalyst) []. (i) decolourises O O - O O - curly arrow from bond to bromine dipoles on or curly arrow to show movement of bonded pair of electrons intermediate carbonium ion/carbocation curly arrow from lone pair on the - ion to carbonium ion ( - loses mark) [5]. (i) electron/lone pair acceptor 5 δ δ- 5 - curly arrow from -bond to Dipoles on the bond and curly arrow from bond to urly arrow from to δ δ- } [4]

2 4. (i) decolourises/not clear/not discolours δ δ- or to - curly arrow from = to dipole on - and curly arrow showing movement of bonded pair of electrons correct intermediate/carbonium ion/carbocation and curly arrow from - to, -dibromopropane as product [5] 5. (a) 5 δ δ : - intermediate curly dipoles shown correctly on the and curly arrow from the bond towards the correct intermediate shown curly arrow from the lone pair or the negative charge on the to the (b) (i) s are diagonal to each other in the trans/ difference clearly shown in a diagram (the product is saturated hence) there is no restricted rotation/single bonds allow rotation/because = prevents rotation [6]

3 6. (a) (i) phosphoric acid/ /sulphuric acid lone/electron pair of electrons acceptor (b) (i) step δ.... Oδ- δ step step O.... O. Step curly arrow from -bond to Step curly arrow from lone pair on the O - to Step curly arrow from O bond to O catalyst no marks because it is not consumed/used up in the reaction/owtte [6] 7. (a) (i) 4.7/ :./: 7./ :. :.06 l (l = 5.5 =) = 45.5 (b) (i) Any two from l l l l l l l l,, -trichloro,, -trichloro,, -trichloro,, -trichloro,,-trichloropropene (trichloropropene scores mark ) marking points: correct numbers,, trichloro propene/prop--ene any two gets mark

4 (c) (i) l l l l l l mark if backbone contains 4 carbons with endbonds and a reasonable attempt has been made e.g used the wrong isomer. max = mark non-biodegradable toxic fumes evolved when burnt l or l or chlorinated organic compounds such as Ol also evolved when burnt [] mark is available if the backbone consists of 4 atoms and a reasonable attempt has been made [] 4

5 9. margarine Ni catalyst hydrogen/ hydrogenated unsaturated vegetable oil/fat poly(propene) equation n n two repeat units (Ziegler) catalyst / high temp/heat/use of an initiator Problems with disposal non-biodegradable/don t decompose/not broken down by bacteria etc when burnt produces toxic fumes Future methods of disposal recycling (to produce new polymers) incineration for energy (production) cracking/owtte (to produce useful organic molecules) use gas scrubbers to reduce toxic fumes QW any two max = 9 Answer is well organised/structure and using at least three of: catalyst, hydrogenation, addition polymerisation, Ziegler, incineration, feedstock, recycling, non-biodegradable, initiator, monomer, unsaturated. in the correct context. [0] 5

6 0. (a) -chloro(--)methylprop--ene/-chloro(--)methylprop--ene (b) l l Backbone of 4 carbons and a reasonable attempt gets mark. []. Bonding: -bond formed by overlap of (adjacent) p-orbitals/ -bond labelled on diagram diagram to show formation of the -bond minimum allowed for diagram mark or Shape/bond angles: is-trans QW tetrahedral around the bond angle = 09 8/ (09-0 ) trigonal planar around each in the = bond angle = 0 (8- ) cis & trans correctly labelled eg but--ene require a double bond because it restricts rotation each in the = double bond must be bonded to two different atoms or groups Allow mark for well constructed answer and use of three terms like: orbital, tetrahedral, trigonal, planar, rotation, spatial, stereoisomers, geometric [0] 6

7 7

OCR AS Chemistry A H032 for first assessment in Complete Tutor Notes. Section: Alkenes Boomer Publications

OCR AS Chemistry A H032 for first assessment in Complete Tutor Notes. Section: Alkenes Boomer Publications OR AS hemistry A 032 for first assessment in 206 omplete Tutor Notes www.boomerchemistry.com Section: 4..3 Alkenes E/Z Isomerism Alkenes Addition polymers 205 Boomer Publications page 43 page 45 page 5