Question

Prelab 8: Due at the start of Lab 8 Lab day Name: Show all work 1. I have a test tube with cobalt nitrate and sodium sulfate in it. How do I safely dispose of this? a. Hide it in my locker for the next student to find. b. Pour it down the drain with lots of water. c. Put it in the waste beaker labeled "Metal salts" d. Drink it. 2. What cations should you be looking for to identify the white pigment in your "white" unknown pigment? 3. What cations should you be looking for to identify the blue pigment in your "blue" unknown pigment? Page 1 of 2

Answer 1

1. Safe Disposal of Cobalt Nitrate and Sodium Sulphate in Laboratory

ans) Pour it down the drain with lots of water.

2. To identify the white pigment in the white unknown pigment, the white color is due the presence of LEAD. And the Pigment is refered as Lead White

3. To identify the blue pigment in the blue unknown pigment, the blue color is due the presence of COBALT. And the Pigment is refered as Cobalt Blue.

Pigments

Indian Yellow: Obtained by the evaporation of cow urine which is fed with dry mango plants.

Carmine : Synthesised from the Species like cochineal and kermes which are scale insects.

Zinc White : It is a Pure Pigment. In recent days used as a supplimentary in lead white and Titanium oil paints.

Cobalt Yellow : Prepared from precipitation of Potassium Cobaltinitrite.

Barium Sulphate: Obtained from natural mineral called barytes

Cadmium Yellow: Basically it is Cadmium Sulphide.

Chrome Yellow: It is Lead (II) Chromate. It is not used as a pigment for paints.

Lead antimonite Yellow: Most ancient inorganic pigment.

Green Earth: Produced from inorganic Pigments.

Red Lead or Minium: Prepared by roasting lead pigment.