Tag: chemistry

Questions Related to chemistry

Which of the following reaction represents the balanced form of conversion of Ca to ammonia?

  1. ${ 2NH } _{ 4 }Cl+Ca\left( OH \right) _{ 2 }\xrightarrow { \triangle } { CaCl } _{ 2 }+{ 2H } _{ 2 }O+{ 2NH } _{ 3 }$

  2. ${ NH } _{ 4 }Cl+Ca\left( OH \right) _{ 2 }\xrightarrow { \triangle } { CaCl } _{ 2 }+{ 2H } _{ 2 }O+{ NH } _{ 3 }$

  3. ${ 2NH } _{ 4 }Cl+3Ca\left( OH \right) _{ 2 }\xrightarrow { \triangle } 3{ CaCl } _{ 2 }+{ 2H } _{ 2 }O+{ 2NH } _{ 3 }$

  4. ${ 4NH } _{ 4 }Cl+Ca\left( OH \right) _{ 2 }\xrightarrow { \triangle } 2{ CaCl } _{ 2 }+{ 2H } _{ 2 }O+{ 2NH } _{ 3 }$


Correct Option: A

Equation for the following reaction.
$Cu+{ xHNO } _{ 3 }\rightarrow Cu\left( { NO } _{ 3 } \right) _{ 2 }+{ 2H } _{ 2 }O+{ 2NO } _{ y }$
Find the value of $x$ and $y$.

  1. $x=4, y= 2$

  2. $x=1, y= 2$

  3. $x=2, y= 2$

  4. $x=4,, y= 1$


Correct Option: A
Explanation:

$Cu+{ 4HNO } _{ 3 }\rightarrow Cu\left( { NO } _{ 3 } \right) _{ 2 }+{ 2H } _{ 2 }O+{ 2NO } _{ 2 }$

$NH _4CI, NH _4NO _3$ and $(NH _4) _2CO _3$ gives $NH _3$ gas on heating.

  1. True

  2. False


Correct Option: B
Explanation:

Reaction:
$NH _4NO _3\rightarrow N _2O+2H _2O$
$NH _4Cl\rightarrow NH _3+HCl$
$(NH _4) _2CO _3\rightarrow 2 NH _3 + H _2O + CO _2$

Which of the following is/are correct?

  1. Hydrolysis of $NCl _3$ gives $NH _3$ and $HClO$

  2. $NH _3$ is less stable than $PH _3$

  3. $NH _3$ is a weak reducing agent compared to $PH _3$

  4. Nitric oxide is paramagnetic


Correct Option: A,C,D
Explanation:

A) $NCl _3$ is hydrolyzed by hot water to release ammonia and hypochlorous acid.
 $NCl _3 + 3H _2O\rightarrow NH _3 + 3HOCl$

B)  $NH _3$ is less stable than $PH _3$, because $NH _3$ is more stable than $PH _3$ due to inter molecular hydrogen bonding.
C) $NH _3$ is a weak reducing agent compared to $PH _3$, because from $NH _3$ to $PH _3$ reducing nature increases down the group.
D) Nitric oxide is paramagnetic, because it is having unpaired electrons.
Hence, options A,C & D are correct.

Ammonia is not a product in the :

  1. hydrolysis of nitrolim

  2. hydrolysis of aluminium nitride

  3. decomposition of ammonium nitrite

  4. hydrolysis of urea


Correct Option: C
Explanation:

$NH _3NO _3\rightarrow N _2O+2H _2O$
Nitrous oxide is produced after decomposition of ammonium nitrite instead of ammonia.

 Which compound does not give ammonia gas on reaction with water ?

  1. $ \mathrm{M}\mathrm{g} _{3}\mathrm{N} _{2}$

  2. $ \mathrm{A}\mathrm{l}\mathrm{N}$

  3. $\mathrm{C}\mathrm{a}\mathrm{C}\mathrm{N} _{2}$

  4. $\mathrm{C}\mathrm{a}(\mathrm{C}\mathrm{N}) _{2}$


Correct Option: D
Explanation:
$Mg _3N _2 + 6H _2O \longrightarrow3Mg(OH) _2 + 2NH _3$

$AlN + 3H _2O \longrightarrow NH _3 + Al(OH) _3$

$2H _2O + Ca(CN) _2 \longrightarrow Ca(OH) _2 + 2HCN$

$CaCN _{2} + 3H _{2}O\longrightarrow$ $CaCO _{3} + 2NH _{3}$

$Ca(CN) _2$ does not produce ammonia on reacting with water.

Assertion (A): In the synthesis of ammonia by Haber's process, mixture of potassium and aluminium oxides can be used as promoter.
Reason (R): Promoter enhances the activity of catalyst.

  1. Both (A) and (R) are true and (R) is the correct explanation of (A)

  2. Both (A) and (R) are true and (R) is not the correct explanation of (A)

  3. (A) is true and (R) is false

  4. (A) is false but (R) is true


Correct Option: A
Explanation:

Promoter enhances the activity of catalyst (here iron), and because of which potassium and aluminium oxides are used as promoter in Haber's process.

Assertion (A): A mixture of $CaCN _2$ and graphite is known as nitration mixture.
Reason (R) : $NH _3$ is collected by downward displacement of air.

  1. Both (A) and (R) are true and (R) is the correct explanation of (A)

  2. Both (A) and (R) are true and (R) is not the correct explanation of (A)

  3. (A) is true and (R) is false

  4. (A) is false but (R) is true


Correct Option: D
Explanation:

$HNO _{3}+H _{2}SO _{4}$ is known as nitration mixture. So, A is wrong.
$NH _{3}$ is collected by downward displacement of air as $NH _{3}$ is lighter than air.

The gas oxygen from thermal decomposition of $\displaystyle (NH _4) _2 \, Cr _2 O _7 $ :

  1. Oxygen

  2. Nitric oxide

  3. Ammonia

  4. Nitrogen


Correct Option: D
Explanation:

$\displaystyle (NH _4) _2 \, Cr _2O _7 \, \overset{\Delta}{\longrightarrow} Cr _2O _3 + N _2 + 4H _2O $

In Haber process of  Ammonia production the element used as catalytic promoter to increase the activity of Iron catalyst is .......................

  1. NI (Nickel)

  2. W (Tungston)

  3. V (Vanadium)

  4. Mo (Molybednum)


Correct Option: D
Explanation:

In Haber process of  ammonia production the element used as catalytic promoter to increase the activity of Iron catalyst is Mo (Molybednum).
$N _2+3H _2  \rightleftharpoons 2NH _3 + 24 \quad kcal$
The temperature is $450^oC$ and  the pressure is 200-250 atm.