aldehydes and ketones

Question 1

can ketones be oxidised

Answer 1

no but aldehydes can

Question 2

what are aldehydes oxidised to

Answer 2

COOH

Question 3

what can aldehydes be reduced to

Answer 3

primary alcohols

Question 4

what can ketones be reduced to

Answer 4

ketones

Question 5

other definition of oxidised

Answer 5

molecule is oxidised when a carbon atom forms a bond with a more electronegative element

Question 6

reduction in organic chem

Answer 6

when a carbon atom forms a bond with a less electronegative element

Question 7

reducing agent

Answer 7

sodium borohydride

Question 8

how to reduce aldehyde or ketone

Answer 8

add solution to test tube and add excess reducing agent AQ
-reaction takes place to reduce to alcohol

Question 9

how is reducing agent made

Answer 9

take solid sodium borohydride and add to water
-salt dissacociates which leave Na+ and BH4- ions

Question 10

what happens when BH4- ions react

Answer 10

one B-H bonds breaks
both electrons in bond go to hydrogen
-giving it negative charge

Question 11

role of negatively charged hydrogen in reduction

Answer 11

reacts with aldehyde or ketone as nucleophile
-BH4- source of hydride ions

Question 12

first step of reduction of aldehydes mechanism steps

Answer 12

lone pair of hydride ions to carbon atom and carbon to oxygen
-lone pair from hydride ion goes to oxygen

Question 13

second step of reduction of aldehydes

Answer 13

lone pair of oxygen to hydrogen plus ion
-alcohol formed OH group

Question 14

first step of reduction of ketones

Answer 14

hydride ions to carbon bond and carbon bond breaks C-0 bond
-O gets lone pair

Question 15

second step of ketone reduction

Answer 15

OH group forms

Question 16

feature of Cdouble O bond in carbonyls

Answer 16

bond is polar so greater electronegativity
oxygen partially negative and carbon positive
-hydride ion will bond with positive carbon
-

Question 17

reduction equations

Answer 17

reactant plus 2 Hydride ions with product and OH on end if aldehyde

Question 18

cyanide composition

Answer 18

carbon triple bonded to nitrogen

Question 19

is cyanide organic or inorganic

Answer 19

inorganic

Question 20

how to name nitriles

Answer 20

-have cyanide in them
-longest chain with nitrile on end

Question 21

bond angle for CN

Answer 21

180

Question 22

HCN

Answer 22

-hydrocyanic acid
-weak acid forms H+ and CN-
-HCN covalently bonded gas not solid ionic salt

Question 23

product when aldehydes and ketones react with cyanide

Answer 23

form hydroxynitriles
-OH and nitrile group

Question 24

2 substances that are sources of cyanide ions

Answer 24

KCN
NaCN

Question 25

other reactants when hydroxynitriles

Answer 25

aqueous potassium cyanide -aqueous sodium cyanide dilute sulfuric acid

Question 26

first step of nucleophilic addition

Answer 26

CN lone pairs to carbon in aldehyde -carbon double to oxygen bond breaks

Question 27

second step of nucleophillic addition hydroxynitriles

Answer 27

intermediate of negative oxygen with CN -lone pairs from oxygen to positive hydrogen formation of OH

Question 28

naming hydroxynitriles

Answer 28

count carbon in nitrile group as position number on in carbon chain and find longest chain -eg 2-ethyl-2-hydroxupentanenitrile

Question 29

full equation for production of 2-hydroxypropannitrile

Answer 29

CH3CHO+ H2SO4 + KCN = CH3CH(OH)CN + KHSO4

Question 30

do hydroxynitriles have optical isomerism

Answer 30

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