Tag: anomalous properties of nitrogen

Questions Related to anomalous properties of nitrogen

In atoms of nitrogen molecule, which type of bond are present ?

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. Hydrogen bond

  2. Ionic bond

  3. Polar covalent bond

  4. Nonpolar covalent bond

  5. Metallic bond

Show answer
Correct Option: D
Explanation:

In atoms of nitrogen molecule, nonpolar covalent bonds are present.
Nonpolar covalent bond is formed between two atoms having zero electronegativty difference.

Identify the true statement regarding nitrates of all metals.

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. All nitrates decompose to give $N{ O } _{ 2 }$

  2. All nitrates are soluble in water

  3. All nitrates are insoluble in water

  4. All nitrates are stable to heat

Show answer
Correct Option: B
Explanation:

Nitrates of divalent and trivalent metals (Mg, Ca, Ba, Pb, Cu, Zn, Hg, Al, Fe etc.) decompose on heating to give reddish brown fumes of nitrogen dioxide.

The nitrates, chlorates, and acetates of all metals are soluble in water.

Nitrates are not stable to heat they decompose to release nitrogen dioxide.


Which molecule is relatively more stable?

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. $O _2$

  2. $H _2$

  3. $Li _2$

  4. $N _2$

Show answer
Correct Option: D
Explanation:

Nitrogen molecule ($\displaystyle N _2$) is relatively more stable. Each $N$ atom has completed its octet and there is a triple bond between two $N$ atoms. In other molecules, there is either a single bond or a double bond between two atoms. A triple bond is stronger than a single or double bond.

The impurities formed during laboratory preparation of dinitrogen from ammonium chloride and sodium nitride is/are:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. $HCl$

  2. $HNO _3  and NO $

  3. $NO _2$

  4. $HNO _2$

Show answer
Correct Option: B,C
Explanation:

$NH _4Cl+NaNO _2 \rightarrow N _2+NaCl+2H _2O$

The impurities formed are small amount of $NO$ and $HNO _3$ , which can be removed by passing gas through aqueous sulphuric acid containing potassium dichromate.

What results in the weak catenation property of nitrogen?

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. Smaller size

  2. Repulsion between non-bonded electrons

  3. Repulsion between protons

  4. High electronegativity

Show answer
Correct Option: B
Explanation:

The weak catenation property of nitrogen is due to lone pair repulsion of lone pair of electrons on nitrogen molecule.

The single $X-X$ bond made by $N$ is weaker than that of $P$ because:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. of repulsion between nitrogen nucleus due to smaller size of nitrogen atom

  2. of repulsion between non-bonded electrons due to smaller size of nitrogen atom

  3. of higher bond enthalpy of nitrogen

  4. all of the above

Show answer
Correct Option: B
Explanation:

The single $N-N$ bonds formed is weaker than single $P-P$ bonds because of lone pair repulsion on small nitrogen molecule.

Which of the following does not contain nitrogen?

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. Proteins in plants and animals

  2. Members of apatite family

  3. Indian saltpetre

  4. Chile saltpetre

Show answer
Correct Option: B
Explanation:

Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite and chlorapatite, with high concentrations of $OH^{-},F{-},Cl{-}$ respectively, in the crystal. Proteins in plants and animals have nitrogen. Chile saltpetre and Indian saltpetre are $NaNO _3$ and $KNO _3$ respectively.

Which of the following gives purest form of nitrogen?

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. Thermal decomposition of ammonium nitrate

  2. Treating aqueous solution of ammonium chloride with sodium nitrite

  3. Thermal decomposition of sodium or barium azide

  4. Liquefaction and fractional distillation of air

Show answer
Correct Option: C
Explanation:

$2NaN _3 \rightarrow 2Na +3N _2$ 

Pure nitrogen can be obtained from thermal decomposition of sodium or barium azide.

Nitrogen can exhibit which of the following oxidation states:

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. $+1$

  2. $+2$

  3. $+3$

  4. all of the above

Show answer
Correct Option: D
Explanation:

Nitrogen forms oxides in which nitrogen exhibits each of its positive oxidation numbers from +1 to +5. $N _2O$ has nitrogen in the +1 oxidation state, $NO$ has +2 and $NO _2$ has +4 oxidation state.

Nitrogen and phosphorus are both in Group 15 of the Periodic Table. Phosphorus forms a chloride with the formula $P{Cl} _{5}$ but nitrogen does not form $N{Cl} _{5}$.
Which statements help to explain this?
1. Nitrogen's outer shell cannot contain more than eight electrons.
2. Nitrogen cannot have an oxidation state of $+5$
3. Nitrogen is less electronegative than phosphorus.

chemistry p- block elements-ii anomalous properties of nitrogen nitrogen - 15 group group 15 elements

  1. 1, 2 and 3 are correct

  2. 1 and 2 only are correct

  3. 2 and 3 only are correct

  4. 1 only is correct

Show answer
Correct Option: D
Explanation:

Only highly electrnegative elements can make nitrogen exhibit +5 oxidation state


We know that, on going from top to bottom in a group, non- metalllic character decreases. The non- metallic character of any element is characterized by its tendency to lose electron i.e electronegativity.
Hence, electronegativity decreases on going from top to bottom in a group.
Therefore, Nitrogen is more electronegative than Phosphorus.

Also, Nitrogen is smaller in size as compared to Phosphorus. Due to its small size, the net electron charge increases. Hence, its nucleus exerts greater force on the electrons.
Thetefore, its tendency to gain electron is more as compared to that of Phosphorus.
That is the reason why, Nitrogen is more electronegative element than Phosphorus.