Class 12th

This is a short answer type question as classified in NCERT Exemplar

The crystal structure of red phosphorus features a sophisticated network of bonding, whereas white phosphorus is made up of P₄ molecules. To avoid natural combustion, white phosphorus must be stored in water, but red phosphorus is stable in air.

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $True$ $$

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $False$ $$

This is a short answer type question as classified in NCERT Exemplar

On interaction with P₄O₁₀ forms an oxide of nitrogen,  N₂O₅, and metaphosphoric acid, 3, nitric acid is formed. HPO₃

HNO₃ + P₄O₁₀→4HPO₃ + 2N₂O₅

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $False$ $$

This is a short answer type question as classified in NCERT Exemplar

Three oxoacids are

(a) HNO₂, Nitrous acid

(b) HNO₃, Nitric acid

(c) Hyponitrous acid, H₂N₂O₂

3HNO₂ + H₂O + 2NO

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $True$

This is a short answer type question as classified in NCERT Exemplar

P₄+6Cl₂→4PCl₃…  (i)

PCl₃+3H₂O→H₃PO₃+3HCl *4

On adding eq. (i) and (ii)

P₄+6Cl₂+12H₂O→4H₃PO₃+12HCl

1 mol of white phosphorus produces 12 mol of HCl

62 g of white phosphorus has been taken which is equivalent to $\frac{\mathrm{N}\mathrm{o}.\mathrm{o}\mathrm{f}\mathrm{}\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{e}\mathrm{s}\mathrm{ }\mathrm{ }}{\mathrm{V}\mathrm{o}\mathrm{l}\mathrm{u}\mathrm{m}\mathrm{e}\mathrm{}\mathrm{i}\mathrm{n}\mathrm{}\mathrm{l}\mathrm{i}\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{s}\mathrm{ }}$ = $\frac{\mathrm{N}\mathrm{o}.\mathrm{o}\mathrm{f}\mathrm{}\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{e}\mathrm{s}\mathrm{ }\mathrm{ }}{\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{r}\mathrm{i}\mathrm{t}\mathrm{y}}$ mol. Therefore 6 molHCl will be formed.

Mass of 6 molHCl=6*36.5=219.0g HCl

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $False$

This is a short answer type question as classified in NCERT Exemplar

P₄O₆ + 6H₂O→4H₃PO₃  (i)

Next is neutralization

4 times H₃PO₃ + 2NaOH→Na₂HPO₃ + 2H₂O  (ii)

On addition of 2 equations

P₄O₆+8NaOH→4Na₂HPO₃+2H₂O

P₄O₆ ( mol.mass )= (4*31+16*6)=220

Number of moles of P₄O₆ = $\mathit{?}/\mathit{V}$    = $\mathit{?}$

The product formed is neutralized 8 moles of NaOH

P₄O₆ = 8* $\mathit{?}$  = $\mathit{?}$  molNaOH

Molarity of NaOH in 1 litre  =  0.1M

 Molarity = $\frac{\mathrm{M}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{r}\mathrm{M}\mathrm{a}\mathrm{s}\mathrm{s}}{\mathrm{G}\mathrm{i}\mathrm{v}\mathrm{e}\mathrm{n}\mathrm{m}\mathrm{a}\mathrm{s}\mathrm{s}}$

 Volume = $\frac{1.1}{220}$  

= $\frac{1.1}{220}$ * $\frac{8.8}{220}$ = 0.4 L