Tag: chemistry

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Questions Related to chemistry

Multiple choice chemistry animal fibre wool - animal fibre wool fibres from animals

The fleece of the sheep along with a thin layer of skin is removed from its body.This process is called___________.

  1. shearing

  2. threading

  3. rearing

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

The fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing. Usually, hair are removed during the hot weather which enables the sheep to survive without their protective protective coat of hair.


Hence, the correct option is $\text{A}$

Multiple choice chemistry animal fibre wool - animal fibre wool fibres from animals

Which of the following represents correct statement(s)?

  1. Two sets of yarn are woven to make a fabric.

  2. The weaving of fabric is done in looms.

  3. The looms are either hand operated or power operated.

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

All of these represent correct statement 

Hence,
option $D$ is correct answer.

Multiple choice chemistry animal fibre wool - animal fibre wool fibres from animals

Select the correct statement from the following.

  1. polyester is obtained from plant stem

  2. jute is the outer covering of coconut

  3. spinning is a process of making fibers

  4. the yarn is made from fibers
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Yarn is made up from fibers.

Hence, 
option $D$ is correct answer.

Multiple choice chemistry animal fibre wool - animal fibre wool fibres from animals

Which kind of wool is common in Tibet and Ladhak? 

  1. Yak

  2. sheep wool

  3. Angora wool

  4. Pashmina wool
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pashmina is a fine type of cashmere wool obtained from the Changthangi goat, native to the high-altitude regions of Tibet and Ladakh. It is prized for its warmth and softness.

Multiple choice chemistry chemical kinetics collision theory collision theory of chemical reactions rate of chemical reaction

Two identical balls A & B having velocity of 0.5 m/s & -0.3 m/s respectively. colloid elastically in 1-0. The velocity of A & B after collision will be?

  1. -0.5 m/s, 0.3 m/s

  2. -0.3 m/s,0.5 m/s

  3. 0.5 m/s, 0.3 m/s

  4. 0.3 m/s,0.5 m/s
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In elastic collision of identical balls, velocities are exchanged. A(0.5) gives 0.3 to B, B(-0.3) gives -0.5 to A. Final: A=-0.3 m/s, B=0.5 m/s. Mass cancels out.

Multiple choice chemistry chemical kinetics collision theory collision theory of chemical reactions rate of chemical reaction

On increasing the temperature by $10^{0}$C:

  1. number of collisions get doubled

  2. value of rate constant does not change

  3. energy of activation increases

  4. number of fruitful collisions gets doubled
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Increasing the temperature of the substance, increases the fraction of molecules which collide with energies greater than $Ea$. For every $10^0 C$ rise in temperature, the fraction of molecules having energy equal to or greater than Ea gets doubled leading to doubling the rate of reaction.

Hence, the number of fruitful collisions gets doubled.

Multiple choice chemistry how far? how fast? collision theory collision theory of chemical reactions rate of chemical reaction

What happen with the rate of the reaction when the frequency and the number of effective collisions between reacting particles increases?

  1. Increases

  2. Decreases

  3. Remains the same

  4. Approaches zero

  5. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The atoms, ions and molecules can react to form products when they collide with enough kinetic energy and at favorable orientation. On increasing the frequency and the number of effective collisions between reacting particles increases the chance of reactants to come together to form a product  that results in the increase of rate of the reaction. 

Multiple choice chemistry how far? how fast? collision theory collision theory of chemical reactions rate of chemical reaction

What causes an increase in effective collisions without increasing average energy?

  1. An increase in the reactant concentration

  2. An increase in the temperature

  3. A decrease in pressure

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

As the concentration of the reactant increases, effective collision between the reactant molecules also increases. And thus, the reaction rate also increases. It is the main principle of the collision theory.

Option  A is the correct answer.