The central nitrogen atom in the no2- ion has nonbonded electron pairs and bonded electron pairs in its valence shell.

1 pair of nonbonded electrons

3 pairs of bonded electrons

Explanation:

N has 5 electrons in its valence shell while O has 6.

Lewis structure of NO²⁻ is in the image.

N is in the middle of the structure because is the less electronegative atom. 3 electrons of this atom are forming the bonds and 2 electrons are nonbonded.

As you can see, N has 3 pairs of electrons forming 3 bonds with Oxygens and there is 1 pair of nonbonded electrons.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2