Reactions And Conditions (Oragnic 1 And Transition Metals)

Question 1

Conditions and product for alkene oxidation

Answer 1

-KMnO4 in cold, aqueous, alkaline solution
-Diol

Question 2

Conditions and product of Acid-catalysed hydration of an alkene

Answer 2

-use of steam
-300 degrees Celsius
-60atm
-phosphoric acid catalyst
-alcohol produced

Question 3

Conditions and product of electrophilic addition of hydrogen halides to an alkene

Answer 3

-gaseous reagent bubbled into liquid alkene
-Halogenoalkane produced

Question 4

Conditions and product of hydrogenation of an alkene

Answer 4

-Hydrogen gas as a reagent
-150 degrees Celsius
-nickel catalyst
-alkane produced

Question 5

Conditions and product and nucleophilic substitution of Halogenoalkanes with cyanide

Answer 5

-KCN or NaCN as a reagent
-in ethanol
-reflux
-forms a cyanide/ nitrile

Question 6

Conditions and product of nucleophilic substitution of Halogenoalkanes with ammonia

Answer 6

-concentrated ammonia in ethanol
-heat in a sealed tube
-excess ammonia to prevent further substitution
-forms an amine

Question 7

Conditions and product of hydrolysis of Halogenoalkanes with aqueous hydroxide ions

Answer 7

-aqueous NaOH or KOH as reagent
-heat under reflux
-forms an alcohol

Question 8

Half equations showing that reaction between ethandioate ions and manganate (VII) ions is autocatalytic

Answer 8

Mn2+ is catalytic because it reacts with MnO4- to make Mn3+.

4Mn2+(aq) + MnO4-(aq) + 8H+(aq) → 5Mn3+(aq) + 4H2O(l)

The Mn3+ then reacts with the C2O42-:

2Mn3+(aq) + C2O42-(aq) → 2Mn2+(aq) + 2CO2(g)

The Mn2+ is regenerated in this step

Question 9

Show how iron can be used a catalyst in the reaction between iodide ions and peroxodisulphate ions

Answer 9

The uncatalysed reaction between iodide ions and persulfate ions is very slow because it involves the reaction between two negative ions. Repulsion between the ions causes a high activation energy.

The reaction is catalysed by Fe²⁺ ions.

In the first stage the Fe²⁺ ions are oxidised to Fe³⁺ ions as they react with persulfate ions, which are reduced to sulfate ions.

Fe²⁺ (aq) + S₂O₈²⁻(aq) → Fe³⁺ (aq) + SO₄²⁻(aq)

Fe³⁺ ions are reduced by iodide ions, to reform Fe²⁺ ions. Iodide ions are oxidised to iodine.

Fe³⁺(aq) + 2I⁻ (aq) → Fe²⁺(aq) + I₂

The overall reaction is:

S₂O₈²⁻(aq) + 2I⁻ (aq) → SO₄²⁻(aq) + I₂

The Fe²⁺ ions are reformed to be used again.

Question 10

Bidentate ligands

Answer 10

-en (H2NCH2CH2NH2) ethylenediamine
-C2O4^2- ethanedioate

Question 11

Multidentate ligand

Answer 11

-EDTA
- 4- charge

Question 12

Oxidation of alcohols

Answer 12

-reagent= potassium dichromate (K2Cr2O7)
-reagent is acidified in sulphuric acid
-heat
-produces aldehydes (primary) or ketones (secondary)

Question 13

Colour change for potassium dichromate

Answer 13

Things that can be oxidised will colour change from orange to green solution

Question 14

Procedure to produce and extract a ketone

Answer 14

-produced with acidified potassium dichromate heated under REFLUX with alcohol
-separated with distillation

Question 15

Procedure to produce an aldehyde

Answer 15

-acidified potassium dichromate heated under distillation with primary alcohol

Question 16

Procedure to produce a carboxylic acid

Answer 16

-acidified potassium dichromate heated under reflux with alcohol
-separated via distillation

Question 17

Conditions and product of elimination of a haloalkanes

Answer 17

-NaOH or KOH dissolved in ethanol (no water present)
-heated
Forms an alkene, water, and halogen ion

Question 18

Colour of [Co(H2O)6]2+

Answer 18

Pink solution

Question 19

Colour of [Co(OH)2(H2O)4]

Answer 19

Blue precipitate

Question 20

Colour of [Co(NH3)6]2+

Answer 20

Orange solution.

Question 21

Conditions and reactant to produce a chloroalkane from an alcohol

Answer 21

-Nucleophilic substitution mechanism (OH is replaced by a chlorine, forming a chloroalkane)

-Reagent=PCl5

-produces HCl (white steamy fumes) and a chloroalkane

Question 22

Conditions and reactant to form a bromoalkane from an alcohol

Answer 22

A reaction mixture of 50% concentrated sulphuric acid and KBr (The KBr reacts with sulphuric to form HBr which reacts with the alcohol)

Forms a bromoalkane and water

Question 23

Reactants and conditions to form an iodoalkane from an alcohol

Answer 23

A mixture of red phosphorus with iodine (the phosphorus reacts with the iodine to form PI3 which reacts with the alcohol)

Forms and iodoalkne and phosphoric acid