Tag: chemistry

Questions Related to chemistry

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

chemistry animal fibre wool - animal fibre wool fibres from animals

  1. shearing

  2. threading

  3. rearing

  4. breeding

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Correct Option: A
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 $\text{A}$

 Which of the following does not yield wool? 

chemistry animal fibre wool - animal fibre wool fibres from animals

  1. Camel

  2. sheep

  3. goat

  4. woolly dog

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Correct Option: D

Which of the following represents correct statement(s)?

chemistry animal fibre wool - animal fibre wool fibres from animals

  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

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Correct Option: D
Explanation:

All of these represent correct statement 

Hence,
option $D$ is correct answer.

Select the correct statement from the following.

chemistry animal fibre wool - animal fibre wool fibres from animals

  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

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Correct Option: D
Explanation:

Yarn is made up from fibers.

Hence, 
option $D$ is correct answer.

Which kind of wool is common in Tibet and Ladhak? 

chemistry animal fibre wool - animal fibre wool fibres from animals

  1. Yak

  2. sheep wool

  3. Angora wool

  4. Pashmina wool

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Correct Option: C

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?

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

  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

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Correct Option: B

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

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

  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

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Correct Option: D
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.

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

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

  1. Increases

  2. Decreases

  3. Remains the same

  4. Approaches zero

  5. None of the above

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Correct Option: A
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. 

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

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

  1. An increase in the reactant concentration

  2. An increase in the temperature

  3. A decrease in pressure

  4. Catalysts

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Correct Option: A
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.

Collision diameter is least in case of:

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

  1. ${ H } _{ 2 }$

  2. $He$

  3. ${ CO } _{ 2 }$

  4. ${ N } _{ 2 }$

Show answer
Correct Option: C
Explanation:

Collision diameter will be least for the low molecular weight.


$d\space \alpha\space \dfrac{1}{M}$

In this case, $Co _2$ has the highest molecular weight.

So, Option C is correct