Tag: study of coal

Questions Related to study of coal

The black thick liquid with unpleasant smell is known as :

chemistry rocks and minerals coal and its products study of coal coal

  1. naphtha

  2. gasoline

  3. coal tar

  4. diesel oil

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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:

chemistry rocks and minerals coal and its products study of coal coal

  1. Aromatic compounds

  2. Aliphatic compounds

  3. Cyclo alkanes

  4. Hetero cyclic compounds

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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?

chemistry rocks and minerals coal and its products study of coal coal

  1. destructive distillation of wood

  2. destructive distillation of bones

  3. destructive distillation of coal

  4. all of these

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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?

chemistry rocks and minerals coal and its products study of coal coal

  1. 1 pound

  2. 10 pounds

  3. 50 pounds

  4. 20 pounds

Show answer
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:

chemistry rocks and minerals coal and its products study of coal coal

  1. asphalt

  2. coal tar

  3. baking ovens

  4. zinc

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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:

chemistry rocks and minerals coal and its products study of coal coal

  1. xylene

  2. anthracene

  3. carbon

  4. naphthalene

Show answer
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.