A weak monobasic acid solution at concentration C has a molar conductivity of ₁ . The solution is then diluted with water at constant temperature until its concentration becomes C 4 . Assuming the acid is very weak (degree of dissociation 1 ), the new molar conductivity ₂ is:

Step-by-step solution

For a weak monobasic acid, Ostwald's dilution law states that the acid dissociation constant K_a = C ^2 1- . Given that the acid is very weak ( 1 ), we can approximate 1 - 1 . This gives K_a C ^2 , or = K_a C . The molar conductivity _m is related to the degree of dissociation by _m = _m^ . Substituting , we get _m = _m^ K_a C . This shows that _m 1 C . When the concentration is changed from C to C 4 , the new molar conductivity ₂ is: ₂ = _m^ K_a C/4 = 2 _m^ K_a C = 2 ₁ . Answer: 2 ₁