Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: Rs.

There are no items in this cart.
Continue Shopping
Grade: 12
        1.What are abrasives?

2.What are macromolecules?
3.What are hygroscopic and hydrophobic substances?
10 years ago

Answers : (1)

Ramesh V
70 Points

1) Abrasives : An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away. While finishing a material often means polishing it to gain a smooth, reflective surface it can also involve roughening as in satin, matte or beaded finishes.

Some naturally occurring abrasives are:

  • Calcite (calcium carbonate),Emery (impure corundum),Diamond dust (synthetic diamonds are used extensively), Novaculite, Pumice dust, Rouge, Sand

2)macromolecules: Any very large molecule, composed of much larger numbers (hundreds or thousands) of atoms than ordinary molecules. Some macromolecules are individual entities that cannot be subdivided without losing their identity (e.g., certain proteins, with molecular weights into the millions). Others (polymers) are multiples of a repeating building block (monomer) in chains or networks (e.g., plastics, cellulose). Most macromolecules are in the size range typical of colloids.

3)hygroscopic and hydrophobic substances:

Hygroscopic substances are those substances that absorb water vapour from the air. The process is called Hygroscopicity.Hygroscopic substances include sugar, honey, glycerol, ethanol, methanol, iodine, many chloride and hydroxide salts, and a variety of other substances

All substances that are water repelling are considered hydrophobic substances.Ex: Oil, Waxes, etc..




10 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution

Course Features

  • 54 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!! Click Here for details