The components of glassy bead $C$ and brown bead $D$ are, respectively:

N a B O_{2}

and

N i O

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

B_{2} O_{3}

and

N i (B O_{2})_{2}

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

N a B O_{2}

and

N i B_{4} O_{7}

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

B_{2} O_{3}

and

N a B O_{2}

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

Open in App

Solution

The correct option is D $B_{2} O_{3}$ and $N i (B O_{2})_{2}$
$A$ is borax or sodium tetraborate $(N a_{2} B_{4} O_{7} .10 H_{2} O)$ .
One mole of $A$ contains 10 moles of water of crystallization.

It is a white crystalline solid and is used in water softening. Its aqueous solution is alkaline due to the formation of sodium hydroxide upon hydrolysis of $N a_{2} B_{4} O_{7}$ . The reaction is as follows:

$N a_{2} B_{4} O_{7} + 7 H_{2} O ⇌ 2 N a O H + 4 H_{3} B O_{3}$

When borax is heated, it loses water and swells into a white mass which is $B$ . The formula is $N a_{2} B_{4} O_{7}$ . The reaction is as follows:

$N a_{2} B_{4} O_{7} .10 H_{2} O h e a t - - \to N a_{2} B_{4} O_{7} B + 10 H_{2} O$

On further heating, $B$ forms glossy solid called borax glass and borax bead (compound $C$ or $B_{2} O_{3}$ ). The reaction is as follows:

$N a_{2} B_{4} O_{7} h e a t - - \to 2 N a B O_{2} + B_{2} O_{3} C$

When $C$ is heated with nickel oxide, a brown bead $D$ is obtained which is nickel metaborate $(N i (B O_{2})_{2})$ . The reaction is as follows:

$B_{2} O_{3} + N i O \to (N i (B O_{2})_{2}) b r o w n b e a d (D)$

Suggest Corrections

Similar questions

N a_{2} B_{4} O_{7} .10 H_{2} O H e a t - -- \to X + N a B O_{2} + H_{2} O

X + C r_{2} O_{3} H e a t - -- \to Y G r e e n c o l o u r

X

Y

$N a B O_{2} + C O_{2} \to A + B$ . A & B are as follows

(N a {B O}_{2} + B_{2} O_{3})

N a_{2} B_{4} O_{7} .10 H_{2} O H e a t - -- \to X + N a B O_{2} + H_{2} O

X + C r_{2} O_{3} H e a t - -- \to Y G r e e n c o l o u r

X

Y

N a_{2} B_{4} O_{7} .10 H_{2} O H e a t \to X + N a B O_{2} + H_{2} O

X + C r_{2} O_{3} H e a t \to

Join BYJU'S Learning Program