Pigment Formation and Properties

The video tutorial demonstrates the process of making the pigment Cobalt Titanite, an opaque blue-green color. The instructor begins by creating a suspension with titanium dioxide and water, then adds cobalt nitrate without specific measurements. The solution is neutralized with sodium hydroxide, filtered, and dried. The dried mass is fired in a kiln to form a fused oxide of cobalt and titanium. After cleaning and processing, the pigment is tested with linseed oil, revealing its thick and opaque properties. The instructor notes the pigment's ability to absorb oil and its potential for color variation.

What is the purpose of adding water to titanium dioxide in the initial steps?

• To dissolve the titanium dioxide

• To form a suspension

• To neutralize the solution

• To react with cobalt nitrate

What is the role of sodium hydroxide in the pigment formation process?

• To dissolve titanium dioxide

• To form a suspension

• To dry the pigment

• To neutralize cobalt nitrate

Why is vacuum filtration used after adding sodium hydroxide?

• To heat the solution

• To dissolve excess cobalt nitrate

• To capture titanium dioxide and cobalt hydroxide

• To dry the pigment

What temperature is used for drying the pigment in an oven?

• 200 degrees Celsius

• 100 degrees Celsius

• 50 degrees Celsius

• 500 degrees Celsius

What is the purpose of kiln firing the pigment?

• To cool the pigment

• To mix the pigment with oil

• To form a fused oxide of cobalt and titanium

• To dissolve impurities

What challenge is faced when removing the pigment from the crucible?

• The pigment is rock solid

• The pigment is too soft

• The pigment is too wet

• The pigment is too light

What is the purpose of using hydrochloric acid in the cleaning process?

• To dissolve the pigment

• To heat the pigment

• To remove unreacted cobalt or titanium oxides

• To dry the pigment

What is the final step before testing the pigment with linseed oil?

• Adding more cobalt nitrate

• Mixing with water

• Grinding into a fine powder

• Kiln firing

What property of the pigment is observed when mixed with linseed oil?

• It changes color to red

• It becomes very thin

• It absorbs a lot of oil and is thick

• It dissolves completely

How can the pigment be made lighter in color?

• By adding more titanium dioxide

• By adding more water

• By using less cobalt

• By increasing the kiln temperature