Conversion of Chlorobenzene to Biphenyl:
The conversion of chlorobenzene (C₆H₅Cl) to biphenyl (C₆H₅-C₆H₅) involves a reaction known as the **Wurtz-Fittig Reaction**. This reaction is a type of cross-coupling reaction where two aryl halides are coupled in the presence of sodium metal.
Reaction:
2 C₆H₅Cl + Na → C₆H₅-C₆H₅ + 2 NaCl
Mechanism:
1. The reaction is carried out in dry ether and requires heat. Sodium metal donates electrons to the chlorobenzene, generating a phenyl radical (C₆H₅•) and sodium chloride (NaCl).
2. The phenyl radicals couple together to form biphenyl (C₆H₅-C₆H₅).
Conditions:
- Sodium metal (Na) is used as a reducing agent.
- The reaction takes place in the presence of anhydrous ether to prevent moisture from interfering with the reaction.
Conclusion:
By heating chlorobenzene with sodium metal in ether, chlorobenzene undergoes a Wurtz-Fittig reaction to form biphenyl.
Identify A in the following reaction. 
A racing track is built around an elliptical ground whose equation is given by \[ 9x^2 + 16y^2 = 144 \] The width of the track is \(3\) m as shown. Based on the given information answer the following: 
(i) Express \(y\) as a function of \(x\) from the given equation of ellipse.
(ii) Integrate the function obtained in (i) with respect to \(x\).
(iii)(a) Find the area of the region enclosed within the elliptical ground excluding the track using integration.
OR
(iii)(b) Write the coordinates of the points \(P\) and \(Q\) where the outer edge of the track cuts \(x\)-axis and \(y\)-axis in first quadrant and find the area of triangle formed by points \(P,O,Q\).