How to score good marks in NEET 2025 - Tips for physics, chemistry & biology

Borax Formula MCQ - Practice Questions with Answers

Edited By admin | Updated on Sep 25, 2023 25:24 PM | #NEET

Quick Facts

  • Borax is considered one the most difficult concept.

  • 12 Questions around this concept.

Solve by difficulty

Identify P, Q and R from the reactions given below, which involves the conversion of borax to boron in the crystalline form.

\mathrm{\text { Borax } \stackrel{\text { HCl }}{\longrightarrow} P \stackrel{\Delta}{\longrightarrow} Q \stackrel{R}{\Delta} \text { Boron }}
 

Study the given statements and identify the incorrect ones with respect to borax and accordingly mark correct option.
I). Aqueous solution of borax can be used as a buffer.
II)  For titration against acids, it is a useful primary standard.
III) 1 mole of borax can be used as a buffer.
IV) There are two triangular \mathrm{BO}_3 units and two tetrahedral\mathrm{BO}_4 units.

Concepts Covered - 0

Borax

It is the most important compound of boron. It is a white crystalline solid of formula Na2B4O7⋅10H2O. In fact, it contains the tetranuclear units [B4O5(OH)4]2-and correct formula; therefore, is Na2[B4O5(OH)4].8H2O. Borax dissolves in water to give an alkaline solution.

\mathrm{Na_{2}B_{4}O_{7}\: +\: 7H_{2}O\: \rightarrow \: 2NaOH\: +\: 4H_{3}BO_{3}}

On heating, borax first loses water molecules and swells up. On further heating it turns into a transparent liquid, which solidifies into glass like material known as borax bead.

\mathrm{Na_{2}B_{4}O_{7}.10H_{2}O\: \overset{\Delta }{\rightarrow}\: Na_{2}B_{4}O_{7}\: \overset{\Delta }{\rightarrow}\: 2NaBO_{2}\: +\: B_{2}O_{3}}

The metaborates of many transition metals have characteristic colours and, therefore, borax bead test can be used to identify them in the laboratory. For example, when borax is heated in a Bunsen burner flame with CoO on a loop of platinum wire, a blue coloured
Co(BO2)2 bead is formed.

"Stay in the loop. Receive exam news, study resources, and expert advice!"

Get Answer to all your questions

Back to top