Question

out of NF3, NF5, HNO3, NO, N2O5 which one is not stable and why?

Answer 1

NF3 IS NOT STABLE.....................................

Answer 2

Answer: Out of all the given compounds, $NF_5$ is unstable.

Explanation:

Nitrogen is the 7th element of the periodic table whose electronic configuration is $1s^22s^22p^3$

Number of valence electrons of this element are 5.

To know the stability, we need to find out the hybridization of each compound. Hybridization is calculated using the Lewis dot structures of all the compounds.

Formula used to calculate the number of atomic orbitals around central metal atom is:

Number of atomic orbitals around central metal atom = Number of bond pairs + Number of lone pairs

Bond pairs for a double bond and triple bond is taken as 1 only.

• Hybridization of nitrogen in $NF_3$

Number of bond pairs = 3

Number of lone pairs = 1

Number of atomic orbitals around Nitrogen atom = 3 + 1 = 4

So, hybridization will be $sp^3$

• Hybridization of nitrogen in $NF_5$

Number of bond pairs = 5

Number of lone pairs = 0

Number of atomic orbitals around Nitrogen atom = 5 + 0 = 5

So, hybridization will be $sp^3d$. As, nitrogen does not have any d-orbitals, therefore this hybridization is not possible and hence, this compound is not possible. Therefore, it is an unstable molecule.

• Hybridization of nitrogen in $HNO_3$

Number of bond pairs = 3

Number of lone pairs = 0

Number of atomic orbitals around Nitrogen atom = 3 + 0 = 3

So, hybridization will be $sp^2$

• Hybridization of nitrogen in $NO$

Number of bond pairs = 1

Number of lone pairs = 0

Number of atomic orbitals around Nitrogen atom = 1 + 0 = 1

So, hybridization will be $sp$

• Hybridization of nitrogen in $N_2O_5$

Number of bond pairs = 3

Number of lone pairs = 0

Number of atomic orbitals around Nitrogen atom = 3 + 0 = 3

So, hybridization will be $sp^2$ and it will be same for both the nitrogen atoms.

Thus, the unstable molecule is $NF_5$