organic MCQ

Question 1

Which statement is not correct about the industrial production of ethanol from ethene at 300 °C?
C2H4(g) + H2O(g) ⇌ C2H5OH(g) ΔH = −46 kJ mol–1
A The reaction is catalysed by an acid.
B The reaction has 100% atom economy.
C An increase in temperature decreases the equilibrium yield of ethanol.
D An increase in pressure increases the value of Kc

Answer 1

D An increase in pressure increases the value of Kc

Question 2

Which compound is produced when 1-phenylethanol reacts with acidified potassium dichromate(VI)?
A C6H5CH2CH2OH
B C6H5CH2CHO
C C6H5COCH3
D C6H5CH(OH)CH3

Answer 2

C
C6H5COCH3

Question 3

Which statement is correct about the production and use of ethanol as a biofuel?
A Biofuel ethanol is produced by the fermentation of glucose in the presence of yeast and air.
B Biofuel ethanol is purified by fractional distillation.
C No carbon dioxide is released when biofuel ethanol is burned.
D Biofuel ethanol burns with a cleaner flame than ethanol made by hydration of ethene.

Answer 3

B
Biofuel ethanol is purified by fractional distillation.

Question 4

Q4. Which compound can be oxidised to form (CH3)2CHCOCH3?
A 2-methylpropan-1-ol
B 2,2-dimethylpropanol
C 2-methylbutan-2-ol
D 3-methylbutan-2-ol

Answer 4

D
3-methylbutan-2-ol

Question 5

Which alcohol forms a mixture of alkenes when dehydrated?
A propan-1-ol
B propan-2-ol
C pentan-1-ol
D pentan-2-ol

Answer 5

D
pentan-2-ol

Question 6

Which compound is formed when 1-phenylethanol reacts with acidified potassium dichromate(VI)?
A C6H5CH2CH2OH
B C6H5CH2CHO
C C6H5COCH3
D C6H5CH2COOH

Answer 6

C
C6H5COCH3

Question 7

In the UK industrial ethanol is now produced by the direct hydration of ethene. This process has largely replaced the fermentation method.
Which is a likely reason for this change of method?
A The direct hydration route produces purer ethanol.
B The direct hydration route employs milder conditions.
C The direct hydration route does NOT use a catalyst.
D The direct hydration route produces ethanol by a slower reaction.

Answer 7

A
The direct hydration route produces purer ethanol.

Question 8

Which statement is correct about both 2-methylbutan-1-ol and 2-methylbutan-2-ol?
A They can be formed by alkaline hydrolysis of esters.
B They can be oxidised by reaction with acidified potassium dichromate(VI).
C They can be formed by hydration of 2-methylbut-2-ene.
D They have four peaks in their 13C NMR spectra.

Answer 8

A
They can be formed by alkaline hydrolysis of esters.

Question 9

Which alcohol can be oxidised by acidified potassium dichromate(VI) but cannot be dehydrated by heating with concentrated sulfuric acid?
A 2,3-dimethylbutan-2-ol
B 2,2-dimethylpropan-1-ol
C 2-methylpropan-2-ol
D pentan-3-ol

Answer 9

B
2,2-dimethylpropan-1-ol

Question 10

Which can be used to distinguish between these two compounds?
(CH3)2CHCH2CHO and (CH3)3CCHO
A Acidified potassium dichromate(VI)
B Fingerprint region of infrared spectrum
C Mr value in high resolution mass
spectrometry
D Tollens’ reagent

Answer 10

B Fingerprint region of infrared spectrum

Question 11

Which statement does not support the suggestion that an unknown organic
compound is
A Its 1H NMR spectrum has 3 peaks with an integration
ratio of 2:3:3
B Its 13C NMR spectrum has 3 peaks.
C Its infrared spectrum has an absorption at 1735 cm−1
D It has 36.36% by mass of oxygen and 9.09% by mass
of hydrogen.

Answer 11

B Its 13C NMR spectrum has 3 peaks.