See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Order of Basicity of Halide Ions **Step 1: Understand basicity relation** Basicity of halide ions is inversely related to their acidity. Stronger conjugate acids produce weaker conjugate bases. $$\text{HX acidity: } HI > HBr > HCl > HF$$ Therefore: $$\text{Basicity: } I^- < Br^- < Cl^- < F^-$$ **Step 2: Explain the trend** - $HI$ is the strongest acid (most acidic) → $I^-$ is the **weakest base** - $HF$ is the weakest acid (least acidic) → $F^-$ is the **strongest base** This is because $F^-$ is the smallest halide with highest charge density, making it most basic and best at accepting protons. **Step 3: Verify option (C)** $$I^- < Br^- < Cl^- < F^-$$ This matches our derived order perfectly. **Why other options fail:** - **(A)** & **(B)** place $F^-$ incorrectly relative to others - **(D)** places $F^-$ and $I^-$ in wrong order **Answer: (C)** is correct.