0.14941 wt% aqueous KCl solution
at 25°c was electrolyzed in a hittorf apparatus using two Ag-AgCl electrods .The cathode reaction was AgCl+ e ~ Ag + Cl- , the anode reaction was the reverse of this .After the experiment ,it was found that 143.34 C charge had been flown through the apparatus and that the cathode compartment contained 120.99g of solution
that was 0.19404wt% KCl by weight.Calculate t+ and t- in the KCl solution
used in the experiment ,neglect the transport of water by ions.
Solution.
(t+)+(t−)=1To determine the number of transfer of potassium ions and chlorine, we write the following formula:
(t+)=QF×Δn(k)Δw=w2−w1
Δw=1000.19404−0.14941=0.04463
Δw=m(solution)m(substance)×100
m(substance)=100Δw×m(solution)m(substance) = 0.0540 g
n(KCl)=Mmn(KCl) = 0.000724 mole
Δn(KCl)=0.000724mole(t+)=143.3496500×0.000724=0.49
(t−)=1−(t+)
(t−)=0.51(t+) = 0.49
(t-) = 0.51
Answer:
(t+) = 0.49
(t-) = 0.51