World of Colors

Q.

Why silver chloride is stored in dark coloured bottles?

Q.

Manganese dioxide gives _______ colour to the glass.

1. Green

2. Purple

3. Yellow

4. Blue

Q. Which of the following dye is used to colour this cloth?

1. Alizarin
2. Ink
3. Indigo
4. Cadmium sulphide

Q. Colours obtained from plants and animals are known as natural dyes.

1. True
2. False

Q. Alizarin Red is an example of synthetic dye.

1. True
2. False

Q.

The colours of aqueous solutions of CuSO₄ and FeSO₄ as observed in the laboratory are:

1. Dark blue and pale green respectively

2. Dark blue and dark green respectively

3. Pale green and light blue respectively

4. Light blue and dark green respectively

Q.

105. Explain the application of mordant dyes to the fabric.

Q. Choose the correct statements from the options given in pair.

1. Alizarin red is a synthetic dye;
   Chromium ions impart green colour to glasses.
2. Alizarin red is a natural dye;
   Manganese dioxide imparts black colour to glasses.
3. Indigo blue is a natural dye;
   Cobalt oxide imparts blue colour to glasses.
4. Indigo blue is a synthetic dye;
   Ferric ions imparts yellow colour to glasses.

Q.

Dyes and ________ are used to impart colour to other objects.

1. flowers

2. pigments

3. chemicals

4. medicines

Q. Colours obtained from plants and animals are known as natural dyes.

1. True
2. False

Q.

Which of the following is an example of a pigment?

1. Silicon dioxide

2. Aluminium oxide

3. Cadmium sulphide

4. Boron oxide