In polyatomic structures, count sigma and pi bonds systematically by identifying single and double bonds.
The structure of pyrophosphoric acid (H4P2O7) consists of an O=P-O-P=O backbone with terminal hydroxyl groups (OH).
Total sigma bonds: 12 (8 single P-O and O-H bonds + 4 sigma components from P=O bonds).
Total pi bonds: 2 (from P=O bonds).
\[ \frac{\sigma}{\pi} = \frac{12}{2} = 6 \]
The ratio of sigma to pi bonds in pyrophosphoric acid is 6:1.
Method used for separation of mixture of products (B and C) obtained in the following reaction is: 
Match the LIST-I with LIST-II for an isothermal process of an ideal gas system. 
Choose the correct answer from the options given below:
Which one of the following graphs accurately represents the plot of partial pressure of CS₂ vs its mole fraction in a mixture of acetone and CS₂ at constant temperature?
