Ordinary glass is primarily made from which basic raw material?

Introduction / Context:
Glass is a common material used in windows, bottles and many everyday objects. It is produced by melting a mixture of raw materials at high temperature. This question asks you to identify the primary basic raw material from which most ordinary glass is made.

Given Data / Assumptions:

• We are talking about typical soda-lime glass used in windows and containers.
• The manufacturing process involves high temperature melting in a furnace.
• Several mineral ingredients may be added to adjust properties.
• The question focuses on the main structural ingredient.

Concept / Approach:
The main raw material for ordinary glass is silica, which is chemically silicon dioxide (SiO2). In practice, silica is obtained from sand. To make soda-lime glass, silica sand is mixed with sodium carbonate (soda) and calcium carbonate (limestone) and then melted. The soda lowers the melting point, and the lime improves chemical durability, but the structural network of the glass is formed by silica. Therefore, among the given options, "sand" correctly identifies the primary material from which glass is made.

Step-by-Step Solution:
Step 1: Recall that common glass is often called silica glass because of its high silicon dioxide content. Step 2: Recognise that silica is naturally found in sand, particularly quartz rich sand. Step 3: Note that the standard industrial batch for soda-lime glass includes sand (SiO2), soda (Na2CO3) and lime (CaCO3). Step 4: Understand that while soda and lime are important additives, the largest component by mass is silica from sand. Step 5: Therefore, the correct answer is that glass is primarily made from sand.

Verification / Alternative check:
Descriptions of glass manufacturing in chemistry and industrial technology textbooks always begin with silica sand as the chief ingredient. The chemical composition of typical soda-lime glass is around 70 percent silica, 15 percent soda and 10 percent lime, plus small amounts of other oxides. Silver iodide is used in some special applications such as cloud seeding and photographic materials, not as a bulk ingredient of glass. Calcium carbonate and lime are components of the mixture but not the sole or primary raw material by volume.

Why Other Options Are Wrong:
Calcium carbonate only and Lime only: These materials (limestone and lime) are added to the glass batch but cannot alone form ordinary glass; without silica, they would not produce typical transparent glass.

Silver iodide crystals: This compound is not a main ingredient in window or container glass and is used for entirely different purposes.

Common Pitfalls:
Some students may remember that limestone is used in glass making and incorrectly choose calcium carbonate or lime as the main ingredient. Others might think of more exotic substances due to special glass types. To avoid confusion, always recall that silica from sand provides the basic network for glass, while other substances modify its melting point, durability and color.

Final Answer:
Ordinary glass is primarily made from Sand (silica) as the main ingredient.