Question

what is the uses of borax​

Answer 1

Answer:

The best-known use for borax is as a cleaner, but you can find the ingredient in many other household products, including: Specialty toothpastes and mouthwashes. Cosmetics such as lotions, skin creams, moisturizers, sunscreen, and acne care products. Paint and ceramic glaze.

Explanation:

Hope it helps

Answer 2

Question :

What is borax and what are its uses?

Class : 11

Chapter : p-block elements

Topic : Boron Family

Answer :

Borax is chemically sodium tetraborate decahydrate which is a white crystalline solid of formula, Na₂B₄O₇.10H₂O .Crude borax naturally available is called tincal.

Borax exists in three different forms :

i) Prismatic or ordinary borax, which is decahydrate or monoclinic and hence the formula is Na₂B₄O₇.10H₂O

ii) Octahedral or Jeweller's borax, which is pentahydrate (Na₂B₄O₇.5H₂O) and is obtained when the solution of Na₂B₄O₇.10H₂O is crystallised above 373°K

iii) Borax glass, which is the anhydrous form (Na₂B₄O₇) and is obtained by heating borax to above its melting point.

Uses of Borax :

a) Borax is used as flux in soldering, welding and in certain metallurgical processes.

b) Borax bead text is used identify coloured basic radicals in qualitative analysis.

c) Borax is used in making optical glass and Pyrex glass.

d) It is used as food preservative.

e) It is used in leather industry for cleaning hides and skin.

Know More :

Borax contains the tetranuclear units [B₄O₅(OH)₄]⁻² and the correct formula therefore is Na₂[B₄O₅(OH)₄].8H₂O. Borax dissolves in water to give an alkaline solution

$\mathrm{Na_2B_4O_7\:+\:7H_2O\rightarrow2NaOH\:+\:4H_3BO_3}$

Aqueous solution of borax acts as acidic buffer because it contains weak acid and its salt with strong base.

$\mathrm{Na_2B_4O_7\:+\:7H_2O\rightarrow2Na[B(OH)_4]\:+\:2H_3BO_3}$

One mole of borax reacts with two moles of HCl or one mole of H₂SO₄. This is because when one mole of borax is dissolved in water, two moles of B(OH)₃ and two moles of [B(OH)₄]⁻ are formed, but only [B(OH)₄]⁻ reacts with HCl. 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 knows as borax bead. It contains NaBO₂ and   B₂O₃ .B₂O3 combines with metal oxides to form metal metaborates as coloured beads.

$\mathrm{Na_2B_4O_7\:+\:7H_2O\overset{\Delta}{\longrightarrow}Na_2B_4O_7\overset{\Delta}{\longrightarrow}2NaBO_2+B_2O_3}$

The metaborates of many transition metals have characteristic colour and therefore, borax bead test can be used to identify them. From the colour of the bead, the nature of the basic radical can be predicted.

Mn(BO₂)₂ - Violet

Cr(BO₂)₃ - Green

Cu(BO₂)₂ - Green

Ni(BO₂)₂ - Violet

Co(BO₂)₂ - Blue

Fe(BO₂)₂ - Yellow

Happy Learning!