solubility 5

 Here is a clean, impactful, CBSE Class 12–friendly explanation of the paragraph you provided, rewritten in simple English for classroom presentation or student notes:

---

🧪 Solubility – Class 12 (CBSE)

---

📖 Definition:

Solubility of a substance is the maximum amount of solute that can be dissolved in a specified amount of solvent at a given temperature.

---

✅ Key Point:

Solubility is not fixed — it depends on:

• Nature of solute and solvent

• Temperature

• Pressure (mainly for gases)

---

🧊 Understanding Solubility in Solids and Gases (in Liquids):

1. Nature of Solute and Solvent:

   • Not all solids dissolve in all liquids.

   • Salt and sugar dissolve easily in water.

   • Naphthalene and anthracene dissolve in benzene, not in water.

   • 📌 Like dissolves like:

     • Polar solutes dissolve in polar solvents

     • Non-polar solutes dissolve in non-polar solvents

---

2. What Happens During Dissolution?

When a solute is added to a solvent:

• Some particles dissolve (dissolution)

• Some particles rejoin the solid (crystallisation)

Over time:

Rate of dissolution = Rate of crystallisation
→ This is called dynamic equilibrium

📌 At this stage, the solution becomes saturated, and its concentration becomes constant.
👉 This concentration = solubility

---

3. For Gases in Liquids:

• Gases like oxygen (O₂) and carbon dioxide (CO₂) can dissolve in water.

• Oxygen dissolves a little → helps aquatic life.

• HCl gas dissolves easily → highly soluble.

📌 Solubility of gases also depends on temperature and pressure (more on that in next slides/notes).

---

Let me know if you’d like this in a printable format, slide design, or with diagrams for classroom use.