CIE AS Level Hydroxy Organic Chemistry

In the reaction pathway below, an alkane is converted into a carboxylic acid through several stages. Which processes occur at stage 1 and at stage 3?

• condensation and combustion

• cracking and dehydration

• cracking and oxidation

• dehydration and combustion

Tags

NGSS.HS-PS1-2

The functional group in a primary alcohol is –CH₂OH. Which reagent reacts with a primary alcohol, under suitable conditions, to give an organic product with the same number of oxygen atoms as the alcohol?

• Al₂O₃

• CH₃CO₂H

• HBr

• Na

The compound shown is menthol, a naturally-occurring alcohol found in peppermint oil. When menthol is heated with concentrated sulfuric acid it reacts. The products that form include compound T.

• 
• 
• 
• 

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-4

Which compound gives an organic product with a lower boiling point when it is heated under reflux with an excess of acidified potassium dichromate(VI)?

• 2-methylbutan-1-ol

• 2-methylbutan-2-ol

• pentan-1-ol

• pentan-2-ol

This question should be answered by considering the reactions of KMnO4 with different functional groups under the stated conditions. The diagram shows the structure of the naturally-occurring molecule cholesterol.

Separate oxidation reactions are carried out using different conditions:

cold, dilute acidified KMnO₄

hot, concentrated acidified KMnO₄.

Which statements about the products formed are correct?

• cold, dilute acidified KMnO₄: number of hydroxy groups present 1, hot, concentrated acidified KMnO₄: number of 6-membered rings remaining 2

• cold, dilute acidified KMnO₄: number of hydroxy groups present 1, hot, concentrated acidified KMnO₄: number of 6-membered rings remaining 3

• cold, dilute acidified KMnO₄: number of hydroxy groups present 3,

  hot, concentrated acidified KMnO₄: number of 6-membered rings remaining 2

• cold, dilute acidified KMnO₄: number of hydroxy groups present 3,

  hot, concentrated acidified KMnO₄: number of 6-membered rings remaining 3

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-5

Geraniol is a constituent of some perfumes. Which statement about geraniol is not correct?

• Geraniol causes hot acidified potassium dichromate(VI) to change colour from orange to green.

• Geraniol decolourises bromine water.

• There are three methyl groups and three methylene (CH₂) groups in geraniol.

• There are two pairs of cis-trans isomers of geraniol.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-1

How many of the isomeric alcohols with the formula C₄H₉OH will produce an alkene that has cis and trans isomers, on treatment with conc. H₂SO₄?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-3

But-2-ene-1,4-diol is converted in two steps through an intermediate X into ketobutanedioic acid.

What could be the reagent for step 1 and the intermediate X?

• reagent for step 1: cold acidified KMnO₄, X: HOCH₂CH₂CH(OH)CH₂OH

• reagent for step 1: hot acidified KMnO₄,

  X: OHCC(OH)CH₂CHO

• reagent for step 1: steam and concentrated H2SO4, X: HOCH₂CH(OH)CH₂CH₂OH

• reagent for step 1: warm acidified K₂Cr₂O₇,

  X: HO₂CCH=CHCO₂H

Many, but not all, organic reactions need to be heated before reaction occurs. Which reaction occurs at a good rate at room temperature (20 °C)?

• CH₃OH + PCl₅ ⟶ CH₃Cl + POCl₃ + HCl

• CH₃CH₂Br + KCN ⟶ CH₃CH₂CN + KBr

• CH₃CH₂OH ⟶ C₂H₄ + H₂O

• CH₃CH₂CN + 2H₂O ⟶ CH₃CH₂CO₂H + NH₃

Tags

NGSS.HS-PS1-5

An organic compound X - is unaffected by hot acidified potassium manganate(VII), - reacts with ethanoic acid in the presence of concentrated sulfuric acid. What is compound X?

• CH₃CO₂C₂H₅

• CH₃CH₂COCH₃

• (CH₃)₃COH

• CH₃CH₂CH(OH)CH₃