Magnesium hydroxide

[alpha-dog]

I never heard of anyone using magnesium hydroxide ( milk of magnesia ). It's suppose to be a strong eletrolyte base material. Can someone tell me whats wrong with that?

[coffeeachiever]

If no one comes up with a good reason why not, I'll get some this weekend and try it with an old wet cell just for kicks.

[Stevo]

I have used Magnesium Sulfate and it worked kinda, but eventually turned the water pink. I used distilled water.

[Q-Hack!]

According to the wiki on Magnesium hydroxide:

Magnesium hydroxide is not very soluble in water, with a Ksp of 1.5x10-11. While the solubility of magnesium hydroxide is low, all of the magnesium hydroxide that does dissolve in the water does dissociate. Since the dissociation of this small amount of dissolved magnesium hydroxide is complete, magnesium hydroxide is considered a strong base.

With a solubility in water of 1.2 mg/100 mL, it won't take much to fully saturate the water.

Let us know how it works.

[hydrotinkerer]

Koh has a ph of 14 and Naoh has a ph of 13. What is the ph of magnesium hydroxide? That would also tell you how strong of a base it would be compared to the others.

[coffeeachiever]

I just got back from Dollar Tree. I went there to get the milk of magnesia. I read the ingredients to see what else was in it. The other ingredients were water and sodium hypochlorite. Isn't that the same thing as bleach?

[Q-Hack!]

Koh has a ph of 14 and Naoh has a ph of 13. What is the ph of magnesium hydroxide? That would also tell you how strong of a base it would be compared to the others.

Magnesium Hydroxide is usually somewhere around 9.5-10.5 PH

I just got back from Dollar Tree. I went there to get the milk of magnesia. I read the ingredients to see what else was in it. The other ingredients were water and sodium hypochlorite. Isn't that the same thing as bleach?

Sodium Hypochlorite or NaClO is in fact bleach... which means that you will end up with a small amount of Chlorine gas. I suspect that the company that makes the stuff you bought is using the NaClO to whiten the dye that is probably also present in that stuff. May not be a big issue as it is probably not all that much by volume.

However, NaClO + H2O yeilds NaCl + H2 +O2
NaCl is salt which is highly corrosive.

All in all there are two ways to look at this. 1) If you are trying to be scientific about the process then stick with materials that you know the composition of. 2) Just try stuff and find something that works. An unbelievable amount of people have used the latter process throughout history and it drives the pure scientist crazy.

The important thing is to have fun with your experiments.

[alpha-dog]

It sounds like magnesium hydroxide may be in 3rd or 4th place on the electrolyte list.

[coffeeachiever]

Once again, this was the Dollar Tree brand. I didn't buy it thinking that I may find a name brand that doesn't have bleach in it. I would still like to try it, just want to see ingredients of other brands before I do.

[cinch]

I'm sure you could call the toll free number on the package and ask them how much of the ingrediants are in the mixture and if there is anything else in there that is not named on the package that may have a negative effect on you or your experiment.Good luck and let us know how it goes!