Substitue for Methylene Chloride?

If the pH is 0 then the hydrogen concentration would be 1 normal.

I will be kind and state categorically that this explanation not only is not correct but certainly didn't come from any reputable Chemistry

101 course.

pH is used as a convenient way to express hydrogen ion concentrations. By definition pH is the negative logarithm of the hydrogen concentration. If the pH is 0 then the hydrogen ion concentration would be 1 normal. Obviously this would be one hellova long way from pure hydrogen. In fact pH has nothing to do with percent.

Every unit change in pH represents a tenfold change in hydrogen ion concentration. The scale is convenient (at least to chemists) in the range of 0 to 14. When the hydrogen ion concentration is greater than

1 normal very few chemists would use the pH scale. When the pH is greater than 14 most chemists will forget pH and use concentration of hydroxide.

The discussion of activity coefficients and pH would not be appropriate here.

Chris,

You're right - methylene chloride is great for cleaning off greasy junk. I know of nothing better. Try using a commercially available drycleaning solvent, like 1,1,1-trichloroethane. It might work.

If you can get your hands on any, ethyl acetate would be worth a try. This stuff is almost edible! (It would dissolve your throat on the way down, but if you diluted it far enough with water it wouldn't hurt you - much.) It has interesting solvent properties that might turn out to be what you want. See if your pharmacist can order you some. I don't know whether this is available cheap.

Paint thinner, stoddard solvent, kerosine, etc., are not good substitutes for methylene chloride. They're less polar, and won't dissolve the more polar materials. Possibly a mixture of one of these with a more polar solvent like denatured alcohol or methyl ethyl ketone might work for you. You'd just have to try it.

Dishwashing compounds - in a dishwasher - can clean aluminum beautifully. They don't stay in contact long enough to significantly etch the aluminum. The key here is hot water, grit and spray force.

Hope this helps. Good luck.

Bruce