You visited us 2 times! Enjoying our articles? Unlock Full Access!

Formation of Complexes

When excess o...

Question

When excess of $N a_{2} S_{2} O_{3}$ is added to dil. $A g N O_{3}$ , a soluble compound ‘X’ is formed. However, when dil. $N a_{2} S_{2} O_{3}$ is added to conc. $A g N O_{3}$ solution, a white precipitate turns yellow and finally black. Precipitate ‘Y’ is formed here. Which is the correct pair?

‘X’ is

A g_{2} S

and ‘Y’ is

N a_{3} [A g (S_{2} O_{3})_{2}]

No worries! We‘ve got your back. Try BYJU‘S free classes today!

‘X’ is

N a_{3} [A g (S_{2} O_{3})_{2}]

and ‘Y’ is

A g_{2} S

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

‘X’ is

A g_{2} S_{2} O_{3}

and ‘Y’ is

A g_{2} S

No worries! We‘ve got your back. Try BYJU‘S free classes today!

‘X’ is

A g_{2} S_{2} O_{3}

and ‘Y’ is

N a_{3} [A g (S_{2} O_{3})_{2}]

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B ‘X’ is $N a_{3} [A g (S_{2} O_{3})_{2}]$ and ‘Y’ is $A g_{2} S$
In excess thiosulphate, dil. $A g N O_{3}$ forms a soluble complex.
$N a_{2} S_{2} O_{3} (e x c e s s) + d i l . A g N O_{3} \to N a_{3} [A g (S_{2} O_{3})_{2}] + N a N O_{3}$
But when conc. $A g N O_{3}$ reacts with dilute thiosulphate, it gives a white precipitate of silver thiosulphate which changes to yellow and finally gives a black precipitate of $A g_{2} S$ .
$d i l . N a_{2} S_{2} O_{3} + 2 A g N O_{3} \to A g_{2} S_{2} O_{3} (w h i t e p p t) + 2 N a N O_{3}$
$A g_{2} S_{2} O_{3} \to A g_{2} S + H_{2} S O_{4}$
So $X = N a_{3} [A g (S_{2} O_{3})_{2}], Y = A g_{2} S$

Suggest Corrections

Similar questions

N a_{2} S_{2} O_{3}

A g N O_{3}

N a_{2} S_{2} O_{3}

A g N O_{3}

A g N O_{3}

N a_{2} S_{2} O_{3}

A g N O_{3}

N H_{4} O H

H C l

X

C u S O_{4}

N a_{2} S_{2} O_{3}

A g^{+}

N H_{4} O H

X

A g N O_{3}

Join BYJU'S Learning Program