Question

Average composition of ordinary glass is:
A) $N{a_2}O.CaO.6Si{O_2}$
B) $N{a_2}O.2CaO.3Si{O_2}$
C) $N{a_2}O.CaO.6Si{O_2}.C{r_2}{O_3}$
D) $N{a_2}O.CaO.PbO.6Si{O_2}$

Answer 1

All glasses are not distinguished by a single chemical composition. Ordinary glass is made up of various components. We have to first look into the chemical reaction involving the formation of ordinary glass and thereby find out the constituents in it.

Complete step by step answer:
Let us first understand the features of glass;
Glass is an optically clear substance created by combining sodium oxide with silicon oxide, boron oxide and adding a trace amount of transition metal oxide to give the glass colour. From silicon dioxide, quartz glass is obtained.
Now, we have to understand that the composition of different substances such as silica, bleaching powder, metal oxides and calcium oxide produces ordinary glass. It is a homogenous silicate combination. Ordinary glass is a substance of supercooled liquid glass that is not crystalline.
There are also different kinds of glasses with different compositions. The red glass incorporates gold and copper in trace quantities. Uranium oxide is present in yellow bottles. Copper oxide or cuprous oxide is found in blue glass. Ferrous oxide or cuprous oxide is present in green glass.
Now, let us look into the chemical reaction in the formation of ordinary glass;
$N{a_2}C{O_3} + 6Si{O_2} + CaC{O_3} \to N{a_2}O.6Si{O_2}.CaO + C{O_2}\,$
The above equation is the overall reaction for fusion of ordinary glass.
Soda lime glass is often referred to as ordinary glasses that are composed of silicon oxide, sodium oxide and calcium oxide. A typical fundamental constituent of glass is silicon dioxide.
Thus, the correct answer is the option A.

ADDITIONAL INFORMATION:
There are four main types of glasses:
Annealed glass
Heat strengthened glass
Tempered or toughened glass
Laminated glass

Note:
Glass types vary greatly in chemical composition and in physical characteristics. However, most types have some characteristics in common. Glass is a bad heat conductor and an insulator because it does not allow electrons to travel through easily.