The equivalent conductance of 0.1 N of `H_(3)PO_(4)` at `18^(@)C` is 96.5 `Omega^(-1) cm^(2) eq^(-1)` if `wedge_(HCI)^(@)=378.3 , wedge_(NaCI)^(@)=109 , wedge_(NaH_(2)PO_(4))^(@)=70 Omega^(-1) cm^(-2)eq^(-1)` respectively calculate the degree of dissoication and dissoication constant for the reaction
`H_(3)PO_(4)rarrH_(2)PO_(4)`

Explanation

To solve the problem, we need to calculate the degree of dissociation (α) and the dissociation constant (K_a) for the dissociation of phosphoric acid (H₃PO₄) into dihydrogen phosphate ion (H₂PO₄⁻) and hydrogen ion (H⁺).

### Step-by-step Solution:

1. **Given Data:**
- Equivalent conductance of 0.1 N H₃PO₄ (Λ) = 96.5 Ω⁻¹ cm² eq⁻¹
- Equivalent conductance of HCl (Λₕₗ) = 378.3 Ω⁻¹ cm² eq⁻¹
- Equivalent conductance of NaCl (Λₙₐₗ) = 109 Ω⁻¹ cm² eq⁻¹
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