Tag: chemistry

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Questions Related to chemistry

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

Arrange the following fibers in the order of increasing strength:

Nylon, Cotton, Wool, Polyester, Silk

  1. Silk, Wool, Cotton, Nylon, Polyester

  2. Wool, Silk, Cotton, Nylon, Polyester

  3. Cotton, Silk, Wool, Nylon, Polyester

  4. Nylon, Cotton, Silk, Wool, Polyester
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

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

  1. It is light weight and very strong

  2. It is shatter proof

  3. Impact resistant

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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.

  1. I, II and IV are correct

  2. I, II & III are correct

  3. I, II are correct

  4. III and IV are correct
Reveal answer Fill a bubble to check yourself
A Correct answer
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'
Multiple choice chemistry combustion and flame structure of flame flame combustion

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.

  1. 1500

  2. 4000

  3. 5000

  4. 1100
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The adiabatic flame temperature of a methane-air flame is approximately 1900-2000 degrees Celsius. Among the provided options, 1500 is the most reasonable estimate for a standard Bunsen burner flame, as heat losses prevent it from reaching the theoretical maximum.

Multiple choice chemistry combustion and flame structure of flame flame combustion

Burning of coal and wood causes  _____________.

  1. pollution of air

  2. decrease of non-renewable source of energy

  3. both (a) and (b)

  4. neither (a) or (b).
Reveal answer Fill a bubble to check yourself
C Correct answer
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. 

Multiple choice chemistry combustion and flame structure of flame flame combustion

The zone of no combustion is _______.

  1. The middle zone

  2. Outermost zone

  3. The base of the flame

  4. Innermost zone
Reveal answer Fill a bubble to check yourself
D Correct answer
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.