Question

The molar conductance of infinite dilution for NAI, CH3COONA, (ch3coo)2 Mg are 10.59,7.10,16.58. calculate molar conductance of MgI2​

Answer 1

Answer:

The molar conductance of MgI₂ at infinite dilution is 23.56 Scm² mol⁻¹

Explanation:

Given:

∧°(NaI) = 10.59 Scm² mol⁻¹

∧°(CH₃COONa) = 7.10 Scm² mol⁻¹

∧°[(CH₃COO)₂Mg] = 16.58 Scm² mol⁻¹

To find:

∧°(MgI₂) = ?

Step-by-step solution:

At infinite dilution each ion has a definite contribution towards the molar conductance of electrolyte and it does not depend on the counter ion present.

Therefore,

∧°(NaI) = λ°(Na⁺) + λ°(I⁻)

∧°(CH₃COONa) = λ°(CH₃COO⁻) + λ°(Na⁺)

∧°[(CH₃COO)₂Mg] = 2λ°(CH₃COO⁻) + λ°(Mg²⁺)

Now,

∧°(MgI₂) = λ°(Mg²⁺) + 2λ°(I⁻)

⇒ ∧°(MgI₂) = λ°(Mg²⁺) + 2λ°(CH₃COO⁻) - 2λ°(CH₃COO⁻) + 2λ°(Na⁺) - 2λ°(Na⁺) + 2λ°(I⁺)

⇒ ∧°(MgI₂) = ∧°[(CH₃COO)₂Mg] + 2∧°(NaI) - 2∧°(CH₃COONa)

⇒ ∧°(MgI₂) = 16.58 + (2 × 10.59) - (2 × 7.10)

⇒ ∧°(MgI₂) = 23.56 Scm² mol⁻¹