Tag: nitrogen and sulfur

Questions Related to nitrogen and sulfur

Geometry of ammonia molecule and the hybridisation of nitrogen involved in it are: 

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

  1. $sp^3$- hybridisation and tetrahedral geometry

  2. $sp^3$- hybridisation and distorted tetrahedral geometry

  3. $sp^2$- hybridisation and trianguklar geometry

  4. none of the above

Show answer
Correct Option: B
Explanation:

(i) Hybridisation $= \frac{1}{2}$ [no.of $e^-$ in valence shell of central atom + no. of monovalent atoms + charge on anion - charge on cation]
(ii) Shape or geometry of molecule depends on lone pair and bond pair of electrons present in it.
Hybridisation  of N in $NH _3$
$=\frac{1}{2}(5+3+0)$
$=4$
$\therefore sp^3$ hybridisation.
$\because$, its has 3 bond pair and 1 lone pair of electrons, so it has distorted tetrahedron shape. 

Carbonyl chloride react with ammonia to give:

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

  1. Urea

  2. Acetone

  3. Acetamide

  4. Chloroform

Show answer
Correct Option: C
Explanation:

carbonyl chloride is $COCl _2$.the reaction between $COCl _2$&$NH _3$ is given as 

$COCl _2+NH _3\longrightarrow ClCONH _2+HCl$

Which statement is false:

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

  1. $\mathrm{N}\mathrm{H} _3$ is a Lewis base

  2. $\mathrm{N}\mathrm{H} _{3}$ molecule is triangular planar

  3. $\mathrm{N}\mathrm{H} _{3}$ does not act as reducing agent

  4. $\mathrm{N}\mathrm{H} _{3}$ (liquid) is used as a solvent

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Correct Option: C

Ammoniacal liquor is :

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

  1. ammonia absorbed in water

  2. ammonium hydroxide

  3. aqueous solution of ammonia

  4. all of the above

Show answer
Correct Option: D
Explanation:

Ammonical liquor is a solution of ammonia in water and is also called as ammonium hydroxide.

Which of the following has maximum complex forming ability with a given metal ion?

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

  1. $ \mathrm{P}\mathrm{H} _{3}$

  2. $ \mathrm{B}\mathrm{i}\mathrm{H} _{3}$

  3. $ \mathrm{N}\mathrm{H} _{3}$

  4. $ \mathrm{S}\mathrm{b}\mathrm{H} _{3}$

Show answer
Correct Option: C
Explanation:

Due to higher tendency of nitrogen to donate its lone pair of electron to form coordinate bond which is not common in other hydrides of VA group elements, it has maximum complex forming ability.

The uses of ammonia is/are :

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

  1. manufacture of Explosives

  2. manufacture of Plastics and Raisins

  3. it is a main source of hydrogen

  4. all of the above

Show answer
Correct Option: D
Explanation:

Uses of ammonia: as a refrigerant, In manufacture of  nitrogeneous fertilizer, Explosives, dry cells, nitrogen gas

Ammonia acts as a :

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

  1. reducing agent

  2. oxidising agent

  3. bleaching agent

  4. both A and C

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Correct Option: A
Explanation:

Ammonia is a strong reducing agent. It dissolves alkali metals and other electropositive metals such as Mg,Ca,Sr,Ba etc. At low concentration deep blue solutions are formed these contain metal cations and solvated electrons.
${ Li }^{ + }+{ e }^{ - }\rightleftharpoons Li\ { Na }^{ + }+{ e }^{ - }\rightleftharpoons Na$

The oxidation state of nitrogen in ammonia molecule is -3.

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

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
The oxidation state of nitrogen in ammonia ($NH _3$) molecule is -3.
Let x be the oxidation state of nitrogen in ammonia. The oxidation state of hydrogen is $ \displaystyle +1$ .
$ \displaystyle x + 3 (+1)=0$
$ \displaystyle x+3=0$
$ \displaystyle x=-3$

What is the action of the Nessler's reagent on ammonia?

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

  1.  brown ppt.

  2. blue ppt.

  3. black ppt.

  4. green ppt.

Show answer
Correct Option: A
Explanation:
Nesseler's reagent is an alkaline solution of Potassium tetraiodomercurate(II) ($K _2[HgI _4]$). It is prepared by combining potassium iodide (KI) and mercuric chloride ($HgCl _2$)
It is made slightly alkaline by adding KOH or NaOH.
On being reacted with gaseous ammonia it produces brown fumes and on being passed through a solution of ammonia, it gives a dirty brown precipitate. The reaction involved is:
$2K _2[HgI _4]+3KOH+NH _3 \rightarrow [OHg _2.NH _2]I+7KI+2H _2O$
The product formed is brown in colour and is used in test for ammonium ion.
It is a qualitative test for ammonia.
 $[OHg _2.NH _2]I$ is called Iodide of Million's base and has structure as:
$H _2N−Hg−O−Hg−I$ which is an insoluble/ brown ppt.

What is the action of the sodium metal on ammonia?

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

  1. Ammonia gas is released

  2. Hydrogen gas is released

  3. Oxygen gas is released

  4. Nitrogen gas id released

Show answer
Correct Option: B
Explanation:
Sodium in ammonia can react in two way:
 1. in the absence of iron (III) catalyst:
the sodium metal gets dissolved in liquid ammonia. The result is a blue solution due to solvated electrons. This is the basis of the Birch Reduction reaction in the presence of alcohol.
2. In the presence of a bit of iron (III) catalyst:
Ammonia gas reacts with sodium metal to form sodium amide ($NaNH _2$) and hydrogen gas. The chemical reaction is as:
$2NH _3+2Na \rightarrow 2NaNH _2+H _2$
in the presence of a bit of an iron(III) catalyst, otherwise its a blue solution only.