3.3.6.3 Infrared spectroscopy

The infrared spectrum of an organic compound is shown.

Which compound produces this spectrum?

• butanone

• ethanol

• pent-2-ene

• propanoic acid

Which compound gives this infrared spectrum?

• 1-bromobutane

• butan-1-ol

• butanal

• butanoic acid

Tags

NGSS.HS-PS4-3

Which of these infrared spectra could represent a carboxylic acid?

• 
• 
• 
• 

This question is about the reaction between propanone and an excess of ethane-1,2-diol, the equation for which is given.

In a typical procedure, a mixture of 1.00 g of propanone, 5.00 g of ethane-1,2-diol and 0.100 g of benzenesulphonic acid, C₆H₅SO₃H, is heated under reflux in an inert solvent. Benzenesulphonic acid is a strong acid.

The products would not have an absorption in the infra-red at

• 1050 cm⁻¹

• 1720 cm⁻¹

• 2950 cm⁻¹

• 3400 cm⁻¹

Tags

NGSS.HS-PS1-7

Which one of the following statements about but-2-enal, CH₃CH=CHCHO, is not true?

• It has stereoisomers.

• It shows a strong absorption in the infra-red at about 1700 cm⁻¹.

• It will turn an acidified solution of potassium dichromate(VI) green.

• It can be dehydrated by concentrated sulphuric acid.

Tags

NGSS.HS-PS1-2