JEE Advanced · 2013 · 02 Jun 2013 · Paper 2 · p-Block Elements

The reactions of

Cl_{2}

gas with cold-dilute and hot-concentrated NaOH in water give sodium salts of two (different) oxoacids of chlorine,

P

and

Q

, respectively. The

Cl_{2}

gas reacts with

S O_{2}

gas, in presence of charcoal, to give a product

R

R

reacts with white phosphorus to give a compound

S

. On hydrolysis,

S

gives an oxoacid of phosphorus,

T

P

and

Q

, respectively, are the sodium salts of

Answer: (A)

Solution

Cl_{2}

reacts with cold-dilute NaOH:

Cl_{2} + 2 NaOH \to NaCl + NaOCl + H_{2} O

NaOCl

is sodium hypochlorite (salt of hypochlorous acid, HClO).

Cl_{2}

reacts with hot-concentrated NaOH:

3 Cl_{2} + 6 NaOH \to 5 NaCl + NaClO_{3} + 3 H_{2} O

NaClO_{3}

is sodium chlorate (salt of chloric acid,

HClO_{3}

).

So

P

and

Q

are sodium salts of hypochlorous and chloric acids.

JEE Advanced · 2013 · 02 Jun 2013 · Paper 2 · Single correct option