Tag: rocks and minerals

Questions Related to rocks and minerals

Calorific value of wood is higher than that of coal.

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient


Correct Option: B
Explanation:

False.
Calorific value of coal is higher than that of wood.

The black thick liquid with unpleasant smell is known as :

  1. naphtha

  2. gasoline

  3. coal tar

  4. diesel oil


Correct Option: C
Explanation:

The black thick liquid with unpleasant smell is known as coal tar.


Hence the correct option is C.

Coal tar is a main source of:

  1. Aromatic compounds

  2. Aliphatic compounds

  3. Cyclo alkanes

  4. Hetero cyclic compounds


Correct Option: A,D
Explanation:

Coal tar is obtained by cooling the gas that is formed during the destructive distillation of coal to approximately ambient temperature. It is a black, viscous liquid composed primarily of a complex mixture of condensed-ring aromatic hydrocarbons.

These are mixtures of phenols, polycyclic compounds and Heterocyclic compounds.

Coal tar which is main source of organic compounds is obtained as by product during?

  1. destructive distillation of wood

  2. destructive distillation of bones

  3. destructive distillation of coal

  4. all of these


Correct Option: C
Explanation:

Coal tar which is main source of organic compounds is obtained as by product during the destructive distillation of coal.

Coal tar is a thick black liquid which is the  by-product of the production of coal gas and coke by the ddestructive distillation of coal which  contains benzene, naphthalene. Coal tar is used for medical and industrial purposes. However, coal is also known as cutar.

Hence option C is correct.

How much coal is needed to supply enough electricity to light ten 100-watt bulbs for about an hour?

  1. 1 pound

  2. 10 pounds

  3. 50 pounds

  4. 20 pounds


Correct Option: A
Explanation:

100 watts = 0.1 KW


For 1 bulb 0.1 KW of power is required, for 10 bulbs that turn out to be 1KW.
Now 10 bulbs have to light for 1 hour that will be 1 KW multiplied by 1 hour = 1 KW

The thermal energy of coal is 6,150 KW/ton, only 40% of the thermal energy of the coal is converted to electricity. so the electricity converted per ton of coal is 0.4 * 6,150 = 2,460 KW/ton.

Number of tons of coal burned for 10 light bulbs for one hour = 1 KW / 2,460KW/ton = 0.0004065 tons 

Multiplying by 2000 pound/ton we get 0.81300 $\approx$ 1 pounds.

Dyes are used for colouring various materials like cloth and plastic. William Perkins, an English Chemist, discovered dyes for colouring from:

  1. asphalt

  2. coal tar

  3. baking ovens

  4. zinc


Correct Option: B
Explanation:
English chemist William Perkin discovered mauveine dye accidently when working with coal tar. Realising the commercial potential of this new purple dye, Perkin patented his synthetic process.

The main constituent of pitch during destructive distillation of coal tar is:

  1. xylene

  2. anthracene

  3. carbon

  4. naphthalene


Correct Option: C
Explanation:

The main constituent of pitch during destructive distillation of coal tar is carbon in various other forms.

Hence option C is correct.

List I List II
A Kerosene I Metalling of roads
B Diesel II Jet aircraft fuel
C Paraffin Wax III Generation of electricty
D Bitumen IV Lubricants
  1. (A)-I, (B)-II, (C)-III, (D)-IV

  2. (A)-I, (B)-III, (C)-IV, (D)-II

  3. (A)-II, (B)-III, (C)-IV, (D)-I

  4. (A)-IV, (B)-II, (C)-III, (D)-I4


Correct Option: C
Explanation:

Kerosene is used in jet aircraft as fuel.


Diesel is used in generation of electricity.

Paraffin wax is used as lubricant.

Bitumen is used for metalling of roads.

Option C is correct.

What happens during carbonisation?

  1. Conversion of organic substance to carbon

  2. Conversion to carbon dioxide

  3. Conversion of carbon to diamond

  4. Conversion of carbon to water


Correct Option: A
Explanation:

During carbonisation an organic substance converts into carbon or a carbon-containing residue through pyrolysis or destructive distillation. 

Which of the following cannot undergo carbonization?

  1. Wood

  2. Dead vegetaion

  3. Minerals

  4. Both A and B


Correct Option: C
Explanation:

Substances which contain organic matter can undergo carbonization. Minerals do not contain any organic matter and cannot undergo carbonization.