Tag: chemistry

Questions Related to chemistry

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

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. $N _2$

  2. $N _2O$

  3. $HNO _3$

  4. $NO _2$

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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:

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. $0$

  2. $+3$

  3. $-3$

  4. $+1$

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Correct Option: B

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

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  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)

Show answer
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:

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. an explosive

  2. a solvent

  3. a paint

  4. a dye

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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 ?

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. Acetic acid

  2. Methane

  3. Urea

  4. All of these

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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 $

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. $NH _{4}CI$

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

  3. Both (a) and (b) above

  4. None of these

Show answer
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 $ :

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  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

Show answer
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 ?

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. $R _3N$

  2. $R _2NH$

  3. $RNH _2$

  4. $NH _3$

Show answer
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?

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

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

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

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

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

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

Show answer
Correct Option: C

Statement 1: $NH _{3}$ can be best collected by water displacement.

Statement 2: $NH _{3}$ is a polar substance.

chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1

  2. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1

  3. Statement 1 is correct but Statement 2 is not correct

  4. Statement 1 is not correct but Statement 2 is correct

  5. Both the Statement 1 and Statement 2 are not correct

Show answer
Correct Option: D
Explanation:

Nitrogen, oxygen and hydrogen can be collected by water displacement because they are only slightly soluble in water. But hydrogen chloride or ammonia can not be separated since both are very highly soluble in water and will react to form hydrochloric acid or ammonium hydroxide respectively so statement 1 is not true.

$NH _3$ is a polar substance so statement 2 is correct.