Question

H CE 0.03496 Na 0.00764 Ac 0.00501 0.00409 Questions 1. A conductivity cell has plane-parallel electrodes, each 2.2 cm x 2.2 cm in area, spaced 2.2 cm apart. When the cell is filled with an electrolyte, the measured conductance is found to be 2,745HS What is the conductivity of the solution? 2. The molar conductances at infinite dilution, o, of aqueous solutions of the strong electrolyte sodium ethanoate (or sodium acetate as it is more commonly known), hydrochloric acid and sodium chloride are 9.10 x 10.42.5 x 10 and 12.81 x 10 S m mol respectively at 25.0°C. What is the molar conductance at infinite dilution of ethanoic acid? Show your calculations.

Answer 1

Ans. The conductance of the cell = 2745 us (61) = 2745 X166s Area of electrode 1. = = 2.2 cm x 2.2cm 4.84 m² Space between the two electrodes = 2.2 m Conductance 1 I Resistance s conductance is ceciprocal ( ļ of Mexistance 2745x10 1oC R = idus klāts = 2 tuss R = 364.305 ore P: Specific. Resistance or resistivity lo space between electrodes A = Area of electrode P = RA 8 = 364.305x4.84 m² = 801:46 5 cm 2.2 cm P = 801.465"cm) Specific conductivity or conductivity CK) = ? 801-46 stim TK = 0.0012 Sum! = 0.0012 Semi! P

Hence, the conductivity of the solution is 0.0012 Sum! Amy @ Molas conductance at infinite dilution (no) for sodium ethanoate lie. ct scoon = 9.10 X103 sm moi! note = 49.5 x 10-3 Airace = 12.81 X10-35 m2 molt According to Kohlytausch's low, red.coone = ficat,coo . dit rungoolt = ? U NEHycoona = x Hot kat .= 9.10 X163 sm? mort (is MH6 = x + + icon = 42.5x108 som mord (iiis 1° Mace. = tinet + ici = 19.81 x163 sm? more Adel equation ü? and this and substpract equation dentycoon + Not + tºit + de- - Nat -die- = 9.10x101. 7:42:5X10---12-81X telecoom + 4+ = ( 9.10 X10 ? + 42. 5 x10°3 – 12:81 810-3) sono = 151.6 x 1923-12.81X163 ) Sma molt COOH = 38.79 x 10 mmol of ethanoic acid The molan conductance at infinita dilution is 38.79X103 sm²molt