Soda-lime glass, the most common type used in windows and bottles, belongs to which family?
- ABorosilicate glass
- BLead-alkali glass
- CSilicate glassCorrect
- DFused silica glass
Solution
Concept
Composition and classification of soda-lime silicate glass
Formula
SiO2 (approx 72%) + Na2O (approx 15%) + CaO (approx 9%)
Step-by-step solution
1. Soda-lime glass is manufactured from silica sand, soda ash, and limestone. 2. The primary network former is silica (SiO2), making it part of the silicate glass family. 3. It represents standard commercial sheet, container, and window glass. Answer: C
Explanation
Soda-lime glass, which constitutes approximately 90% of all manufactured glass including window panes and bottles, is made by melting silicon dioxide (silica, ~70-75%), sodium carbonate (soda, ~15%), and calcium carbonate (lime, ~9%). It is fundamentally classified under the silicate glass family. Therefore, option C is correct.
Why the other options are wrong
A) Borosilicate glass contains boron trioxide for thermal shock resistance (e.g. Pyrex). B) Lead-alkali glass (flint glass) contains lead oxide for optical prisms and decorative crystal. D) Fused silica glass consists of pure SiO2 without fluxing agents.
Shortcut
Soda-Lime Glass = Soda + Lime + Silica = Silicate Glass.
Common mistake
Confusing common soda-lime glass with borosilicate glass (Pyrex/laboratory glass containing boron trioxide).
Correct answer: C) Silicate glass