Tag: chemistry

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Multiple choice chemistry hydrogen and its compounds heavy water study of heavy water hard water and soft water

Heavy water $\displaystyle \left( { D } _{ 2 }O \right) $ is used in Atomic Reactors as -

  1. Coolant

  2. Controller

  3. Shield

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

Moderator. e.g. , Heavy water, is a substance used in nuclear reactors of reduce the speed of fast Neutrons produced by nuclear fission.Moderator. e.g. , Heavy water, is a substance used in nuclear reactors of reduce the speed of fast Neutrons produced by nuclear fission.Moderator. e.g. , Heavy water, is a substance used in nuclear reactors of reduce the speed of fast Neutrons produced by nuclear fission.'

Multiple choice chemistry hydrogen and its compounds heavy water study of heavy water hard water and soft water

Heavy water is used in nuclear reactors as:

  1. source of $\alpha-$ particles

  2. slowing down the speed of high energy neutrons

  3. transporting heat of the reactor

  4. heating purpose
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heavy water is used in nuclear reactors, where it acts as a neutron moderator to slow down neutrons so that they are more likely to react with the fissile $U^{235}$ than with $U^{238}$, which captures neutrons without fissioning.

Multiple choice chemistry hydrogen and its compounds heavy water study of heavy water hard water and soft water

$ \displaystyle 4{ D } _{ 2 }O+3Fe \xrightarrow[]{red-hot} Fe _{3}O _{4}+gas.$ The gas produced in the above reaction is:

  1. $ \displaystyle O _{2}$
  2. $ \displaystyle H _{2}$
  3. $ \displaystyle D _{2}$

  4. none
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Reaction:

$ \displaystyle 4{ D } _{ 2 }O+3Fe \xrightarrow[]{red-hot} Fe _{3}O _{4}+ D _2$. The gas produced in the reaction is deuterium.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

A drop each of two non-corrosive and non-irritating liquids A and B at a temperature of $22^o$C are placed on the skin. Liquid 'A gives a more cooling sensation than liquid B. Which of the following can be said about the liquids A and B?

  1. Liquid A has higher boiling point than that of liquid B

  2. Liquid A has higher latent heat of vaporization than that of liquid B.

  3. Liquid A has lower latent heat of vaporization than that of liquid B.

  4. The boiling points of liquid A and B are equal.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Light A gives a more cooling sensation than liquid B means liquid A is early vaporised than liquid B. Thus, liquid A has less B P and lower latent heat of vaporisation than that of liquid B.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

At higher altitudes the boiling point of liquid is lowered because :

  1. temperature is low

  2. pressure is high

  3. temperature is high

  4. atmospheric pressure is low
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A liquid reaches its boiling point when its vapor pressure is equal to the atmosphere around it.

 Because the presence of solute lower the vapor pressure, the boiling point is raised

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Which of the following solutions will have the highest boiling point?

  1. $0.1M\quad { FeCl } _{ 3 }$
  2. $0.1M\quad { BaCl } _{ 2 }$
  3. 0.1M $NaCl$
  4. 0.1 M $Urea$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Boiling point elevation depends on the solvent, of course, but we're assuming water, and upon the concentration of the solute and how many particles into which the solute breaks. Colligative properties like boiling point elevation, depend on the total number of particles in solution. The solvent used here is water. So elevation in boiling point will be above a boiling point of water for all solutions.
Boiling point $\alpha$ van't hoff factor
$FeCl _{3}      ,  i=4$
$BaCl _{2}       ,  i=3$
$NaCl   ,    i=2$
so  $FeCl _{3}$  has higher value of $i$
so it has Highest BP.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

The ability of the particles of a gas or liquid to move out and fill up all available space is called.

  1. Melting

  2. Transfusion

  3. Evaporation

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

Diffusion refers to a process by which molecules intermingle as a result of their kinetic energy of random motion. Molecules of gases are in constant motion and make numerous collisions with the partition.