Question

Observe the following reactions

Which are common for both Y and W? I. Four P-OH bonds II. Two P-H bonds III. Two \(P=O\) bonds IV. One P-O-P bond

• A. I, III, IV only
• B. I, II, III only
• C. II, III, IV only
• D. III, IV only

Hint:

Pyro acids commonly contain bridging oxygen bond called P-O-P linkage.

Answer 1

The Correct Option is C

Concept: Phosphorus oxides react with water to form oxyacids. These acids undergo further chemical transformations. We identify products carefully.

Step 1: Find compound X and Y. Reaction: \[ P_2O_3+3H_2O\rightarrow2H_3PO_3 \] So \[ X=H_3PO_3 \] Now reaction with phosphorus trichloride produces pyrophosphorous acid. Final compound Y contains:

• Two P-H bonds

• Two \(P=O\) bonds

• One P-O-P bond

Step 2: Find compound Z and W. Reaction: \[ P_4O_{10}+6H_2O\rightarrow4H_3PO_4 \] Further condensation gives pyrophosphoric acid. This compound W contains:

• Two \(P=O\) bonds

• One P-O-P bond

• Four P-OH bonds

Step 3: Find common features. Common features in Y and W: \[ II.\;Two\;P-H\;bonds \] \[ III.\;Two\;P=O\;bonds \] \[ IV.\;One\;P-O-P\;bond \] Hence correct answer: \[ \boxed{C} \]