Tag: world energy needs

Questions Related to world energy needs

What is the percent of carbon present in pitch?

chemistry world energy needs coal petroleum non-renewable sources of energy

  1. 20

  2. 40

  3. 60

  4. 92-94

Show answer
Correct Option: D
Explanation:

The percent of carbon present in pitch is 92-94%.

Coal tar is the main source of:

chemistry world energy needs coal petroleum non-renewable sources of energy

  1. aromatic compounds

  2. alicyclic compounds

  3. aliphatic compounds

  4. nitro compounds

Show answer
Correct Option: A
Explanation:

Coal tar is a complex mixture of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds but it is mainly used as the main source for aromatic compounds.

When fractional distillation of coal tar is carried out, the percentage of which fraction is maximum?

chemistry world energy needs coal petroleum non-renewable sources of energy

  1. Pitch

  2. Gasoline

  3. Lubricating oil

  4. None of these

Show answer
Correct Option: A
Explanation:

When fractional distillation of coal tar is carried out,  the maximum percentage is of pitch. Pitch is undistilled residue. It is about 50-60%.

When a fractional distillation of coal tar is carried out, the percentage of which fraction is minimum?

chemistry world energy needs coal petroleum non-renewable sources of energy

  1. Light oil or crude naphtha

  2. Middle oil or carbolic oil

  3. Heavy oil or creosote oil

  4. Green oil or anthracene oil

Show answer
Correct Option: A
Explanation:

During the fractional distillation of coal tar, the fraction which has minimum percentage is light oil or crude naphtha. It is obtained only $1.5-2\%$ in the distillation.

Separation of two substances by crystallisation depends upon their differences in:

chemistry world energy needs coal petroleum non-renewable sources of energy

  1. densities

  2. solublity

  3. melting point

  4. boiling point

Show answer
Correct Option: B
Explanation:

Separation of $2$ substances by crystallization depends upon their difference in solubility as more soluble impurity will go into the solution and less soluble component will crystallize out.

Which is not a non-renewable source of energy?

physics world energy needs coal petroleum non-renewable sources of energy

  1. coal

  2. petrol

  3. wind

  4. petroleum gas

Show answer
Correct Option: C
Explanation:

Coal, petroleum gas and petrol are fossil fuels. Fossil fuels are good for one time use. But wind is a renewable source of energy.