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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: gpflwkd123 on August 13, 2011, 04:38:09 pm

Title: question about electrolysis
Post by: gpflwkd123 on August 13, 2011, 04:38:09 pm

hey guys, i have a question about electroylsis that's been really confusing to me :S
so. when you electrolyse NaCl solution, i was told that the products will differ on the concentration of Cl- but i don't understand why :(
Can someone explain it to me please?

Thanks

Title: Re: question about electrolysis
Post by: Graphite on August 13, 2011, 05:24:40 pm

Because the electrochemical series only predicts reactions based on standard conditions i.e. 1M solutions

Title: Re: question about electrolysis
Post by: ellecee on August 13, 2011, 05:26:40 pm

Although water is a stronger reductant than Cl-, and theoretically should be oxidised in preference, Cl- ions are also oxidised in experiments as they have similar Eo values. To my knowledge, if the conc. is higher than 1M NaCl, Cl2 will be the most common product as the higher concentration makes the oxidation of Cl- more favourable.

Title: Re: question about electrolysis
Post by: Graphite on August 13, 2011, 05:28:03 pm

Why does a higher concentration favour the oxidation of Cl-? Please explain.