Australia's Science Forum

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

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?

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.

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.

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.