Why is solid `CaCl_2` spread on roads in cold countries during winter season ?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Composition of CaCl2:**
- Calcium chloride (CaCl2) is an ionic compound made up of calcium ions (Ca²⁺) and chloride ions (Cl⁻). It is a solid at room temperature.

2. **Behavior of CaCl2 in Cold Conditions:**
- When solid CaCl2 is spread on icy roads, it interacts with the ice (solid water, H2O).

...