Tag: group 15 elements

Questions Related to group 15 elements

Nitrogen is liberated by the thermal decomposition of only :

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

  1. $NH _4NO _2$

  2. $NaN _3$

  3. $(NH _4) _2Cr _2O _7$

  4. All of these

Show answer
Correct Option: D
Explanation:

Nitrogen is liberated by the thermal decomposition of ammonium nitrite $(NH _4NO _2), NaN _3, (NH _4) _2Cr _2O _7$

-1/3 oxidation state of nitrogen will be obtained in case of ________.

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

  1. hydroxylamine

  2. oxime

  3. hydrazoic acid

  4. none of these

Show answer
Correct Option: C
Explanation:

nitrogen show oxidation state of -1\3 in hydrazoic acid 

$H-N={ N }^{ + }={N:}^{ - }$

The correct order of stability is

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

  1. ${ N } _{ 2 }>{ N } _{ 2 }^{ + }>{ N } _{ 2 }^{ - }$

  2. ${ N } _{ 2 }>{ N }^{ - } _{ 2 }>{ N } _{ 2 }^{ + }$

  3. ${ N } _{ 2 }^{ + }>{ N }^{ - } _{ 2 }>{ N } _{ 2 }$

  4. None of these

Show answer
Correct Option: A
Explanation:

Bond order for $N _2=3$

Bond order for $N _2^+=2.5$
Bond order for $N _2^-=2$
Bond order $\propto$ Stability of molecule.
Therefore, the correct order of stability is:
$N _2>N _2^+>N _2^-$

Which of the following has $p\pi -d\pi $ bonding?

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

  1. ${ NO } _{ 3 }^{ - }$

  2. ${ CO } _{ 3 }^{ - }$

  3. ${ BO } _{ 3 }^{ - }$

  4. ${ SO } _{ 3 }^{ - }$

Show answer
Correct Option: D
Explanation:

$p\pi-d\pi$ bonding includes d-orbitals,if you observe the options only S belongs to $3^{rd}$ period and has d-orbitals(though unoccupied in ground state).

Other options $C$ and $N$ belongs to $2^{nd}$ period while B belongs to $1^{st}$ period and doesn't have d-orbitals.

Which of the following statements is correct ?

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

  1. In trisilylamine $p\pi - d\pi $ back bonding takes place.

  2. These are two $p\pi - d\pi $ bonds in molecule.

  3. Fraction of s-character in hybride around the central atom in molecule is 0.5

  4. ${\left( {{\text{C}}{{\text{H}} _{\text{3}}}} \right) _{\text{3}}}{\text{COH}}$ is more acidic than ${\left( {{\text{C}}{{\text{H}} _{\text{3}}}} \right) _{\text{3}}}{\text{SiOH}}$

Show answer
Correct Option: A

Which of the following is true for $N _{2}O _{5}$?

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

  1. Paramagnetic

  2. Anhydride of $HNO _{2}$

  3. Brown gas

  4. Exist in solid In form of $[NO^{+} _{2}][NO _{3}^{-}]$

Show answer
Correct Option: D
Explanation:

$N _{2}O _{5}$ in solid form exists as $NO _{3}^{-}$ and $NO _{2}^{-}$.

Which forms $p\pi - p \pi$ multiple bonds with itself and with C and O?

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

  1. P, As

  2. N, As

  3. N, P

  4. N

Show answer
Correct Option: D
Explanation:

N forms such bonds as,
$N \equiv N;  -C \equiv N;  N\equiv O$

Nitrogen differs from P, As, Sb and Bi in the following properties :

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

  1. It forms diatomic molecule.

  2. It is not able to extent its coordination number beyond four.

  3. Nitrogen does not function as a Lewis acid whereas P, As, Sb and Bi do so.

  4. In all the properties given above.

Show answer
Correct Option: D
Explanation:

As vacant d-orbital are present in P and other elements of this group except N so they can expand their valency and forms stable pentavalence product but due to absence of d-orbitals nitrogen cannot form pentavalence products.

It forms diatomic molecule $N _2$.
Nitrogen does not function as a Lewis acid due to absence of d-orbitals and it is a Lewis base due to presence of lone pair.

The anomalous behaviour of nitrogen is due to:

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

  1. small size and high electronegativity

  2. non availability of d-orbitals in valency shell

  3. ease of multiple bond formation

  4. all are correct

Show answer
Correct Option: D
Explanation:

Nitrogen differs from other members of the group due to its smaller size, high electronegativity, high IE and non availability of d-orbitals. Nitrogen has unique ability to form $p\pi - p\pi $ multiple bonds with itself and with other elements having small size and high electronegativity.

An element X combines with hydrogen to form a compound $XH _3$. The element X is placed on the right side ofthe periodic table. What is true about the element X?
A. Has 3 valence electrons.
B. Is a metal and is solid.
C. Is a non-metal and is a gas.
D. Has 5 valence electrons.
E. $XH _3$  reacts with water to form a basic compound?

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

  1. A, B and C

  2. B,C and D

  3. C, D and E

  4. E, A and B

Show answer
Correct Option: C
Explanation:

Here, $X$ is nitrogen with atomic number 7 and electronic configuration $ { 1s }^{ 2 }{ 2s }^{ 2 }{ 2p }^{ 3 } $ 

It is a non metal belonging to group 15.
Solution of ammonia In water is alkaline in nature and is highly soluble in water.