Voltaic cell solutions

[Krysia Lee]

Hello
I just want to check this. If I'm making acidified solutions to use in a voltaic cell do i add 15mL of 0.1M sulfuric to 1L solution I'm making. Eg Zinc sulfate etc. Or should I use a higher conc. of acid???
I'd appreciate your help.
Thanks Krysia

[Rowyrow]

Why does it have to be acidified? I set this up on monday with just the straight sufate solutions and a voltmeter and it worked fine. Or am I getting confused?

[smiley]

We have just completed the world's biggest EEI's on Voltaic cells, trying to reach a target voltage with various pairings of metals and their salts. We just used mostly Nitrates & their corresponding electrode. e.g. Zinc Nitrate with a Zn electrode, and Copper Nitrate with a Cu electrode. No need to acidify. We started with 1M as a demo, but quickly diluted.

I could be wrong, but too much acid will just generate it's own reaction, instead of the electron transfer you're looking for.

[Rowyrow]

we used copper sulfate, zinc sulfate, magnesium sulfate and ferric sulfate with their corresponding metal electrodes and a potassium nitrate salt brigde (could use sodium chloride) all solution were 0.1 M but the studenets where just comparing the voltage from each metal. so yeah no acid.

[smiley]

We use the "Student Cells" from Westlab (& lots of other places too) and they are GREAT! It's taken me a couple of years to build up enough for 2 classes, but they are definitely worth it!

Even just buying the little porous pots, and using them with beakers is a great idea.