Some Important Compounds Of Boron
Chapter Name : The P- Block Elements |
Sub Topic Code : 102_11_11_04_01 |
Topic Name : Some Important Compounds Of Boron |
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Sub Topic Name : Borax |
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Introduction
• Borax is the most important compound of boron. • It is a white crystalline solid of formula Na2[B4O5 (OH)4].8H2O • Borax dissolves in water to give an alkaline solution • 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. • The metaborates of many transition metals have characteristic colours and, therefore, borax bead test can be used to identify them. • 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.
Pre-Requisites:
Elements, periodic table, Group
Activity:
• Group 13 has aluminium, boron which are important industrial elements.
Real Life Question:
What is boron used for?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| P block elements | Have the last electron in the outermost p orbital. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Borax powder | Important compound of boron used for cleaning. |
Real life uses :
• An important compound of boron is borax used for cleaning.
Places to visit :
Chemistry lab, kitchen.
Practical examples around us
| Examples | Explainations |
|---|---|
| Borax powder | Used for cleaning. |
What you learn in Theory:
• Borax is the most important compound of boron. • It is a white crystalline solid of formula Na2[B4O5 (OH)4].8H2O • Borax dissolves in water to give an alkaline solution • 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. • The metaborates of many transition metals have characteristic colours and, therefore, borax bead test can be used to identify them. • 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.
What you learn in Practice:
• Group 13 has aluminium, boron which is important industrial elements.