Tag: heavy water

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Questions Related to heavy water

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

Which of the following is not a deuterolysis reaction

  1. $SO _{3}+D _{2}O\rightarrow D _2SO _{4}$
  2. $CaC _{2}+2D _{2}O\rightarrow Ca(OD) _{2}+C _{2}D _{2}$
  3. $Mg _{3}N _{2}+6D _{2}O\rightarrow 3Mg(OD) _{2}+2ND _{3}$
  4. $AlCl _{3}3D _{2}O\rightarrow Al(OD) _{3}+3DCl$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option $A$ is not a deuterolysis reaction. It is not a chemical reaction at all. 

Deuterolysis reactions are reactions in which a salt reacts with heavy water to give a base and an acid.

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

Which of the following statement regarding $D _{2}O$ is correct?

  1. It is an isotope of hydrogen

  2. It is used as a bleaching agent

  3. It is used as a moderator in atomic reactors

  4. It is used as a coolant in atomic reactors
Reveal answer Fill a bubble to check yourself
C,D Correct answer
Explanation

$D _2O$  is used as a moderator in atomic reactors and as coolant in atomic reactors.

The chain reaction in a reactor is sustained by the free neutrons coming from one fission being absorbed by a Uranium nucleus, which then fissions itself. The probability of this absorbtion is increased if the neutrons are moving slowly. The purpose of the moderator is to slow the neutrons down. 
Lighter nuclei make better moderators than heavy nuclei. If a neutron were to hit an infinitely heavy nucleus, it would bounce off in a different direction with the same velocity. When a neutron hits a nucleus of atomic mass one head on, it comes to a complete stop. 
So, we want to use light nucleus. The reason water $(H _2O)$ is unsuitable is that it is likely to absorb the neutrons instead of slowing them down. The probability of water absorbing a neutron is more than $200$ times higher than the probability of deuterium (which already has a neutron) doing so.
Hence, options C and D are correct.

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

The products formed when heavy water is reacted with magnesium nitride, is/are _______.

  1. $NH _{3}Mg\left ( OH \right ) _{2}$
  2. $NH _{3}Mg\left ( OD \right ) _{2}$
  3. $ND _{3}Mg\left ( OH \right ) _{2}$
  4. $ND _{3}Mg\left ( OD \right ) _{2}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Mg _{ 3 }{ N } _{ 2 }+6{ D } _{ 2 }O \rightarrow 2{ ND } _{ 3 }+ 3Mg(OD) _{ 2 }$

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

Heavy water is used as a:

  1. fuel in engines

  2. semiconductor

  3. moderator in nuclear reactors

  4. insulator in steam engines
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Answer:-

Heavy water is used in certain types of nuclear reactors, where it acts as a neutron moderator to slow down neutrons so that they are more likely to react with the fissile uranium-235 than with uranium-238, which captures neutrons without fissioning.

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

Heavy water is used as _______ in nuclear reactor.

  1. controller

  2. moderator

  3. promoter

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heavy water acts as a neutron moderator in nuclear reactors 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 fission process.

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

Heavy hydrogen has __  neutron and  _ proton in the nucleus.

  1. 2 and 1

  2. 1 and 2

  3. 1 and 1

  4. 2 and 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Deuterium is called as a heavy hydrogen.
Heavy hydrogen $\left( _{ 1 }^{ 2 }{ D } \right) $ $=$ $1$ neutron
                                            $1$ proton
                                            ${ 1e }^{ - }$