Tag: ammonia

Questions Related to ammonia

$\displaystyle Al{ Cl } _{ 3 }\left( aq \right) +{ NH } _{ 3 }\left( aq \right) + { H } _{ 2 }O\rightarrow $
Which of the following is one of the products obtained from the reaction above?

  1. $\displaystyle AlN$

  2. $\displaystyle Al{ H } _{ 3 }$

  3. $\displaystyle Al$

  4. $\displaystyle { Al\left( { NO } _{ 3 } \right) } _{ 3 }$

  5. $\displaystyle { Al\left( OH \right) } _{ 3 }$


Correct Option: E
Explanation:

${ AlCl } _{ 3 }+3{ NH } _{ 3 }+3{ H } _{ 2 }O\rightarrow Al\left( OH \right) _{ 3 }+3{ NH } _{ 4 }Cl$

When heated $NH _3$ is passed over $CuO$, evolved gas is :

  1. $N _2$

  2. $N _2O$

  3. $HNO _3$

  4. $NO _2$


Correct Option: A
Explanation:

When  ammonia is heated and passed over solid copper(II)oxide at high temperatures, nitrogen gas is formed.

$2NH _3(g)+3CuO(s)\rightarrow N _2(g)+3Cu(s)+3H _2O(g)$

Hence option A is correct.

When excess of ammonia is used:


 $3Cl _2+8NH _3$$\longrightarrow$$A+B$

When excess of chlorine is used:

$3Cl _2+4NH _3$$\longrightarrow$$C+D$

The oxidation state of nitrogen in compound $D$ is:

  1. $0$

  2. $+3$

  3. $-3$

  4. $+1$


Correct Option: B

An alkaline earth metal $(M)$ dissolves in liquid ammonia forming a deep blue-black solution. The reaction involved is:

  1. $M + 2NH _{3} \rightarrow M(NH _{2}) _{2} + H _{2}$

  2. $M + xNH _{3} \rightarrow [M(NH _{3}) _{x}]$

  3. $M + 2NH _{4}OH \rightarrow M(OH) _{2} + 2NH _{3}$

  4. $M + (x + 2y) NH _{3}\rightarrow [M(NH _{3}) _{x}]^{2+} + 2[e(NH _{3}) _{y}]^{-}$. (e represents electron)


Correct Option: D
Explanation:

An alkaline earth metal $(M)$ dissolves in liquid ammonia forming a deep blue-black solution. The reaction involved is $M + (x + 2y) NH _{3}\rightarrow [M(NH _{3}) _{x}]^{2+} + 2[e(NH _{3}) _{y}]^{-}$ (e represents electron).
An alkaline earth metal $(M)$ will lose two electrons to form $M^{2+}$ ions.
$M \rightarrow M^{2+}+2e^-$
Both $M^{2+}$ ions and electrons are solvated (surrounded by ammonia molecules to form $[M(NH _{3}) _{x}]^{2+} + 2[e(NH _{3}) _{y}]^{-}$).

When ammonium nitrate is mixed with aluminium powder, we get 'ammonal', which is:

  1. an explosive

  2. a solvent

  3. a paint

  4. a dye


Correct Option: A
Explanation:
Ammonal is an explosive made up of ammonium nitrate and aluminium powder, in which the ammonium nitrate functions as an oxidizer and the aluminium as fuel.

The organic compound which was first prepared in the laboratory ?

  1. Acetic acid

  2. Methane

  3. Urea

  4. All of these


Correct Option: C
Explanation:

Urea was first discovered in urine in 1727 by the Dutch scientist Herman Boerhaave, This was the first time an organic compound was artificially synthesized from inorganic starting materials, without the involvement of living organisms.

$NH _{3} + HCI  \rightarrow $

  1. $NH _{4}CI$

  2. $NH _{3}CI + H$

  3. Both (a) and (b) above

  4. None of these


Correct Option: A
Explanation:
$NH _{3} + HCI  \rightarrow NH _4Cl$
Ammonia reacts with $HCl$ to form ammonium chloride($NH _4Cl$).

Select the correct options about the solubility of the following species in $ H _2O$ and $ NH _3 $(aq).
$AgF, AgCN, AgCl, Agl, CaF _2, CaCl _2 $ :

  1. $AgF$ and $CaCl _2 $ are soluble in $H _2O$

  2. $AgCN$ and $AgCl$ are soluble in $NH _3$

  3. $AgI$ and $CaF _2$ are soluble in $ H _2O $ and $ NH _3 $ (aq) both

  4. None of these


Correct Option: A,B
Explanation:

A. $AgF$ and $CaCl _2$ are polar compounds. Hence, they are soluble in water which is a polar solvent. Thus, the option A is correct.

B. $AgCN$ and $AgCl$ form complexes with ammonia as ammonia is a very good ligand. Hence, $AgCN$ and $AgCl$ are soluble in ammonia. Thus, the option B is correct.

C. $CaF _2$ and $AgI$ are insoluble in water. Thus, the option C is incorrect.

Which has the highest $pK _b$ value ?

  1. $R _3N$

  2. $R _2NH$

  3. $RNH _2$

  4. $NH _3$


Correct Option: D
Explanation:

Ammonia is a weak base so it has pK value of 4. So the order of basicity is ammonia<primary<tertiary amines <secondary amines. This order depends on steric hindrance. The size of alkyl group is more than that of hydrogen atom. So alkyl group hinders the attack of hydrogen atom and decreases the basicity of molecule. So more the number of alkyl groups lesser will be its basicity.

Which of the following forms hydrogen bond?

  1. $\displaystyle { CH } _{ 4 }$

  2. $\displaystyle { CO } _{ 2 }$

  3. $\displaystyle { NH } _{ 3 }$

  4. $\displaystyle { N } _{ 2 }$

  5. $\displaystyle { O } _{ 2 }$


Correct Option: C