The limiting molar conductivities ( _m^ ) of Ba(OH)₂ , BaCl₂ , and NH₄Cl at 298 K are 525.0 , 279.0 , and 149.0 S cm ^2 mol ⁻¹ respectively. The limiting molar conductivity of NH₄OH at the same temperature is:

Step-by-step solution

Using Kohlrausch's law of independent migration of ions: _m^ (NH₄OH) = ^ (NH₄^+) + ^ (OH^-) We can express this in terms of the given strong electrolytes: _m^ (NH₄OH) = _m^ (NH₄Cl) + 1 2 _m^ (Ba(OH)₂) - 1 2 _m^ (BaCl₂) Substituting the given values: _m^ (NH₄OH) = 149.0 + 1 2 (525.0) - 1 2 (279.0) _m^ (NH₄OH) = 149.0 + 262.5 - 139.5 _m^ (NH₄OH) = 272.0 S cm ^2 mol ⁻¹ Answer: 272.0 S cm ^2 mol ⁻¹