See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Acidic Strength Comparison ## Option (A): $HClO_4 > HClO_3 > HClO_2 > HClO$ ✓ **CORRECT** **Reasoning:** For oxoacids of the same element, acidic strength increases with the number of oxygen atoms (higher oxidation state of central atom). - $Cl$ oxidation states: $+7$ (in $HClO_4$), $+5$ (in $HClO_3$), $+3$ (in $HClO_2$), $+1$ (in $HClO$) - More oxygens → greater electron withdrawal from O-H bond → easier H⁺ release - **Order is correct** ## Option (B): $H_3PO_4 > H_3PO_3 > H_3PO_2$ ✗ **INCORRECT** - $H_3PO_2$ is actually **strongest** (monobasic acid with P-H and P-OH bonds; P-H is readily ionizable) - Correct order: $H_3PO_2 > H_3PO_4 > H_3PO_3$ ## Option (C): $HClO_4 > HBrO_4 > HIO_4$ ✓ **CORRECT** **Reasoning:** For oxoacids with same structure but different halogens, acid strength depends on electronegativity. - Electronegativity: $Cl > Br > I$ - More electronegative central atom → stronger acid - $HClO_4$ is strongest oxyacid known - **Order is correct** ## Option (D): $BF_3 > BCl_3 > BBr_3$ ✗ **INCORRECT** - These are Lewis acids, not Brønsted acids - Correct order: $BF_3 > BCl_3 > BBr_3$ (by electronegativity argument) - However, experimental data shows $BCl_3 > BF_3$ due to B-halogen bond strength considerations **Answer: (A) and (C)**