Question

In the manufacture of glass, the addition of $Mn{{O}_{2}}$ gives:
(a)- Yellow color
(b)- Red color
(c)- Violet color
(d)- Pink color

Answer 1

Hint: Many metal compounds are used to add color to the glass because it is the property of the glass which makes it attractive. $Mn{{O}_{2}}$ is manganese dioxide and it is used to add the color into the glass which has the lowest wavelength in VIBGYOR.

Complete answer:
Glass is a solid substance, which is non-crystalline and it is used in many things like windows, optics, tableware, colorful bottles, jars, etc. So, while the production of glass, its color is transparent.
So, to give color to the glass-metal compounds are introduced into the glass. These molecules or compounds are metal oxides, sulfides, and others that are gradually added to the glass. These must be added to the glass when it is in a molten state.
So, the manganese dioxide having formula $Mn{{O}_{2}}$ is added to the molten glass to give violet or purple color.
Other compounds like cadmium sulfide give yellow color, cobalt oxide gives blue-violet color, nickel oxide also give violet color, selenium oxide gives a red color, chromic oxide gives emerald green color, uranium oxide gives yellow-green color, tin compounds will give white color, the lead compound will be yellow color, iron oxides will give green and brown color, etc.

Therefore, the correct answer is an option (c)- Violet color.

Note:
There is a non-metal oxide that is also used to give color to the glass, i.e., carbon oxide can also give Amber-brown color. Sodium Nitrate is used as a decoloring agent in the glasses.