Chemical Technology Multiple Choice Questions on “C3 Compounds – Acetone”.
1. Which among the following methods is not used for the manufacture of acetone?
a) Catalytic hydrogenation of isopropanol
b) Oxidation of butane
c) Oxidation of propylene
d) Hydration of propylene
Answer: d
Clarification: Acetone is widely manufactured by catalytic hydrogenation of isopropanol or oxidation of butane or oxidation of propylene or fermentation of molasses. Isopropanol is manufactured by
hydration of propylene.
2. Combined oxidation dehydrogenation is a better alternative to dehydrogenation of isopropanol for the manufacture of acetone.
a) True
b) False
Answer: a
Clarification: A mixture of air and isopropanol vapour is passed through a catalyst usually silver at 400°C. This method can be used as an alternative to the common method as it produces a better yield.
3. What is the ideal pressure for the manufacture of acetone by dehydrogenation of isopropanol?
a) 50-100atm
b) 900-1000atm
c) 250-350atm
d) 3-4atm
Answer: d
Clarification: The reaction is favoured at low pressure to reduce reactor size and water circulation load for a given plant capacity.
4. What is purity of acetone produced by the dehydrogenation of isopropanol?
a) 50%
b) 60%
c) 80%
d) 99%
Answer: d
Clarification: Acetone produced is 99% pure with 90% yield. Fractionalization increases the purity of acetone.
5. Which catalyst is used in Wacker’s process?
a) Copper
b) Arsenic
c) Palladium (II) chloride
d) Silver
Answer: c
Clarification: In Wacker’s process ethylene is oxidized to acetaldehyde which is finally oxidized to acetone in the presence of catalyst (Palladium (II) chloride.) This reaction is considered as the first homogeneous catalysis with organopalladium chemistry applied.