On fusion of a mixture of `Na-2CO_3` and ` CaCO_3` with silica at `1500^@C`, a liquid consisting of silicates of sodium and calcium is formed. On cooling . Liquid become viscous and eventually ceases to flow . It becomes solid and is known as glass. By varying the proportions of the three basic ingredients and by adding other substances, the properties of glass can be altered, Glass can be represented as `R_2 O. MO.6SiO_2`, where `R= Na` or `K, M = CaBa, Zn` or `pbSiO_2` may be replaced by `Akl_2 O_3 , b_2 O_3` or `P_2 O_5`. Coloured glasses are obtained by adding certain metallic oxides or salts in the fused mass, Glass is attached by `HF` and this property is used to make marking on the glass , This is known as etching . The glass on rapid coolling becomes brittle and fragile . The artciles of glass are cooled neither slowly nor very rapidly . The process of gradual cooling of glass iscalled annealing .
The acid that cannot be stored in glass is .

Options

A. `HF`
B. `HCl`
C. HBr`
D. Hl`

Explanation

To determine which acid cannot be stored in glass, we need to analyze the properties of glass and its interaction with various acids.

### Step-by-Step Solution:

1. **Understanding Glass Composition**:
Glass is primarily made from a mixture of sodium carbonate (Na2CO3), calcium carbonate (CaCO3), and silica (SiO2). When these materials are fused at high temperatures (around 1500°C), they form a liquid that solidifies into glass upon cooling.

**Hint**: Remember that glass is formed from silicates, which are compounds containing silicon and oxygen.

2. **Identifying the Properties of Glass**:
Glass has certain properties that make it susceptible to reactions with specific substances. One important property is that glass can be etched or marked by certain acids.

**Hint**: Consider which acids are known to react with silicates.

3. **Analyzing the Acids**:
The question presents several acids: HF (hydrofluoric acid), HCl (hydrochloric acid), HBr (hydrobromic acid), and HI (hydroiodic acid). We need to determine which of these can react with the silicates in glass.

**Hint**: Focus on the reactivity of hydrofluoric acid with silicates.

4. **Reactivity of Hydrofluoric Acid**:
Hydrofluoric acid (HF) is known to react with silica and silicates, forming soluble fluorosilicates. This means that HF can corrode the glass structure, leading to its dissolution.

**Hint**: Recall that HF is often used in industrial processes for etching glass due to its ability to react with silica.

5. **Conclusion**:
Since HF reacts with the silicates in glass and can cause damage, it is the acid that cannot be stored in glass. The other acids listed (HCl, HBr, and HI) do not have the same corrosive effect on glass.

**Final Answer**: The acid that cannot be stored in glass is **HF (hydrofluoric acid)**.