1. A simple fractional tube is packed with ____________
a) Wooden beads
b) Plastic beads
c) Metal beads
d) Glass beads
Explanation: A simple fractional tube is packed with glass beads. The fractional distillation column is set up with the heat source at the bottom on the still pot.
2. Fractional distillation is different from distillation because of the presence of ____________
a) Fractionating column
b) Condenser
c) Distillation flask
d) Conical flask
Explanation: Fractional distillation is different from distillation because of the presence of fractionating column. A laboratory fractionating column is a piece of glassware used to separate vaporized mixtures of liquid compounds with close volatility.
3. The beads are provided in fractional column for ____________
a) Vapours to generate
b) Vapours to condense
c) Vapours to evaporate
d) All of the mentioned
Explanation: The beads are provided in fractional column for vapours to condense. The fractional distillation column is set up with the heat source at the bottom of the still pot.
4. Select the incorrect statement from the following options.
a) Fractionating columns are available in various design and size
b) Fractionating columns are available according to one fixed standard
c) A simple fractionating column is a tube packed with glass beads
d) Fractional distillation is the process of separation of different gases from air
Explanation: Fractionating columns are available in various design and sizes and not according to one fixed standard.
5. Which of the following gases cannot be separated from air using fractional distillation?
a) Argon
b) Oxygen
c) Helium
d) Nitrogen
Explanation: Helium gas cannot be separated from air using fractional distillation. Fractional distillation is used in air separation, producing liquid oxygen, liquid nitrogen, and highly concentrated argon.
6. Initially, the temperature at the top of the column is _______________ than at its bottom.
a) Greater
b) Lesser
c) Equal
d) None of the mentioned
Explanation: The temperature at the top of the column is lesser than at its bottom. The two major types of distillation columns used are tray and packing columns.
7. Which of the following is more suitable for fractional distillation process?
a) Oil bath
b) Water bath
c) Glycerine bath
d) None of the mentioned
Explanation: Oil bath is the most suitable option for the fractional distillation process. Vacuum distillation systems operate at reduced pressure, thereby lowering the boiling points of the materials. Anti-bumping granules, however, become ineffective at reduced pressures.
8. Number of steps required for the separation of two liquids in fractional distillation is _________
a) 1
b) 2
c) 3
d) 4
Explanation: Number of steps required for the separation of two liquids in fractional distillation is 2. Vacuum distillation systems operate at reduced pressure, thereby lowering the boiling points of the materials. Anti-bumping granules, however, become ineffective at reduced pressures.
9. The organic liquid in steam distillation vaporizes at ____________
a) Lower temperature than its boiling point
b) Higher temperature than its boiling point
c) At its boiling point
d) None of the mentioned
Explanation: The organic liquid in steam distillation vaporizes at lower temperature than its boiling point.
10. Steam distillation process is used to separate substances which are ____________
a) Steam volatile
b) Steam volatile and immiscible with water
c) Steam volatile and miscible with water
d) All of the mentioned
Explanation: Steam distillation process is used to separate substances which are steam volatile and immiscible with water. It is a type of distillation of a liquid in a current of steam, used especially to purify liquids that are not very volatile and are immiscible with water.