Wednesday, March 24, 2010

Give the chemical name for urea

  • Carbamine

Give the chemical name for water glass

  • Sodium silicate

Give the chemical name for verdigris

  • Basic copper carbonate.

What is white lead?

White lead is basic lead carbonate.

Uses Of Slaked Lime

  • For white- washing buildings
  • Making mortar
  • Neutralising the acidity of the soil
  • Softening water(Clarke's process)

Uses Of Coke

  • As a smokeless fuel
  • In metallurgy
  • In the production of water gas & producer gas.

Uses Of Bone Charcoal

  • Decolourising brown sugar
  • Purifying organic liquids

Uses Of Sugar Charcoal

  • In the manufacture of artificial diamonds

Uses Of Wood Charcoal

  • As a fuel
  • Adsorbent
  • Decolourising agent
  • Constituent of gun powder.

Important Use Of Graphite

In the manufacture of lead pencils, electrodes,refractory crucibles, lubricants & in nuclear reactors to absorb neutrons.

Tuesday, March 23, 2010

Important Processes

  • Bosch Process : Hydrogen
  • Castner Process : Sodium
  • Down Process : Sodium
  • Nelson Process: NaOH
  • Caster- Kellner cell : NaOH

Write the chemical names for the following liquids

  • Iodoform : Tri-iodio-methane
  • Chloroform : Tri-chloro-methane
  • Carbolic acid : Phenol
  • Tincture of iodine : Alcoholic solution of iodine
  • Hypo solution : Sodium thiosulphate

Give the chemical name for fire damp

Methane

Give the chemical name for laughing gas

Dinitrogen oxide

Thursday, March 4, 2010

Determination of DRC of Fresh Latex

AIM:

To determine the DRC of Fresh latex.

APPARATUS:

  • Cotton waste
  • Rubber stopper
  • 50ml Erlenmeyer flask ( dried)
  • Electronic balance
  • 250ml beakers(2)
  • Air oven
  • Water bath

REAGENTS:

  • Distilled water
  • 1% Acetic acid solution

PROCEDURE:

  • Shake the given sample of latex bottle.
  • Transfer 20-25ml latex into a 50ml erlenmeyer flask provided with a stopper.


  • Weigh about 10-20gm latex using an electronic balance.
  • Note the weight taken.
  • Pour the weighed latex into a 250ml beaker. A duplicate should also be done.
  • Add equal amount of distilled water.
  • Add about 2-3ml of 1% Acetic acid per gram of latex sample.


  • Keep the solution undisturbed for 15 minutes on a water bath.
  • When the serum is clear, filter it through whatman No: 1 filter paper.
  • Thickness of the coagulum is reduced to about 2mm by hand roller.
  • Collect any small particles of coagulum present in the beaker by rubbing it with main bulk.
  • Wash the coagulum with running water for at least 6 changes of water.
  • Dry the coagulum in an air oven at a temperature of 70 degree Celsius for 1 day or for 50 degree Celsius for 2 days.
  • Cool for a while & take the final weight.

CALCULATION:

DRC of fresh latex =(weight in gm of dried film/weight in gm of latex sample taken)*100