Tag: chemistry

Questions Related to chemistry

Arrange the following fibers in the order of increasing strength:

Nylon, Cotton, Wool, Polyester, Silk

chemistry substances in daily use polyester and acrylic rayon and nylon synthetic fibres

  1. Silk, Wool, Cotton, Nylon, Polyester

  2. Wool, Silk, Cotton, Nylon, Polyester

  3. Cotton, Silk, Wool, Nylon, Polyester

  4. Nylon, Cotton, Silk, Wool, Polyester

Show answer
Correct Option: B
Explanation:

Tensile strength of polymer increases with increase in chain length and cross-linking of polymer chains. According to this, the tensile strength of wool < silk < cotton < nylon < polyester. Artificial fibers like nylon and polyester are designed specially to have more tensile strength.

Why PET is increasingly used for making bottles, jars and utensils?

chemistry substances in daily use polyester and acrylic rayon and nylon synthetic fibres

  1. It is light weight and very strong

  2. It is shatter proof

  3. Impact resistant

  4. All of the above

Show answer
Correct Option: D
Explanation:

PET is light weight, naturally colourless with high transparency, strong and impact resistant. It is shatter proof. All these properties of PET makes a highly more suitable material than glass for making bottles, jars, utensils etc.

A common form of polyester is :

chemistry substances in daily use polyester and acrylic rayon and nylon synthetic fibres

  1. Nylon

  2. Rayon

  3. PET

  4. Acrylic

Show answer
Correct Option: C
Explanation:

A common form of polyester is PET.

Which gas reduces the oxygen-carrying capacity of the blood?

chemistry air and water pollution control ways to prevent air pollution ways to reduce air pollution reducing air pollution

  1. $CO$

  2. $CO _2$

  3. $NO _2$

  4. $SO _2$

Show answer
Correct Option: A
Explanation:

Carbon monoxide reduces the oxygen-carrying capacity of the blood.

The percentage of water in a human body is:

chemistry water in our life where do we get water from? why conserve water uses of water

  1. 80%

  2. 70%

  3. 60%

  4. 50%

Show answer
Correct Option: B
Explanation:

The percentage of water in human body is $70\%$. 


Different parts of the body contains different percentage of water and the average $\approx 70\%$.

The process of losing water by plants is called:

chemistry water in our life where do we get water from? why conserve water uses of water

  1. evaporation

  2. transpiration

  3. condensation

  4. translocation

Show answer
Correct Option: B
Explanation:

The process of losing water by plants is called transpiration. It is the process where plants absorb water through the roots and then give off water vapour through pores in the leaves.

Study the given statements and select the correct answer.


(I) Lipids are macromolecules but obtained under-macromolecular fraction due to their insoluble nature in the aqueous medium of a cell.
(II) Water is the most abundant chemical in a living organism.
(III) The first respiratory substrate is lipid.
(IV) Dihydroxyacetone occurs in d and l form.

chemistry water in our life where do we get water from? why conserve water uses of water

  1. I, II and IV are correct

  2. I, II & III are correct

  3. I, II are correct

  4. III and IV are correct

Show answer
Correct Option: A
Explanation:
(I) Lipids are micromolecules as they are not polymers. These are monomers made up of three fatty acids attached to a glycerol. Because these are hydrophobic, they are obtained under the macromolecule fraction.
(II) Water is the most abundant chemical in the living organism.
(III) Glucose acts as the first respiratory substrate.
(IV) Dihydroxyacetone occurs in both the D and L form.
Hence, the correct answer is 'I, II and IV are correct'

What is the maximum possible temperature( in $^0 C$) of a Bunsen burner flame? Assume that the gas is pure methane and that it is pre-mixed with sufficient air to permit complete combustion.

chemistry combustion and flame structure of flame flame combustion

  1. 1500

  2. 4000

  3. 5000

  4. 1100

Show answer
Correct Option: A

Burning of coal and wood causes  _____________.

chemistry combustion and flame structure of flame flame combustion

  1. pollution of air

  2. decrease of non-renewable source of energy 

  3. both (a) and (b)

  4. neither (a) or (b).

Show answer
Correct Option: C
Explanation:

Burning of coal and wood causes air pollution and because of burning of coal and wood there is decrease in amount of non-renewable sources. 

The zone of no combustion is _______.

chemistry combustion and flame structure of flame flame combustion

  1. The middle zone

  2. Outermost zone

  3. The base of the flame

  4. Innermost zone

Show answer
Correct Option: D
Explanation:

Innermost zone is the zone of no combustion. It is also called as dark zone which is formed around the wick of the candle flame.