Hi Jennie,
I just use plain ol' $1.20 a gallon generic ammonia from the
cleaning aisle in the grocery store.
I responded to a similar post yesterday explaining that what you buy
in the grocery store is NOT just ammonia, as ammonia is a lethal
gas. What you buy is ammonium hydroxide, which is ammonia gas
dissolved in water. I was apologetic for being nit-picking, but
please bear with me as there’s a reason for my nit-picking.
I use it two parts ammonia to one part water (it probably should
be the other way around, but I'm impatient).
What you are purchasing is mostly water, so to say you use two parts
ammonia to one part water is incorrect and I would suggest that you
probably can’t even get that much ammonia gas into water. I could
look up the solubility of ammonia gas in water in one of my
chemistry books, but it’s not necessary. My point is to ask if all
this “generic” or “pure” ammonia is the same concentration across the
board?
You can’t possibly compare strengths of your mixed “ammonia solution”
(eg two parts to one part water), without also stating its
concentration. For example, the ammonium hydroxide (or ammonia
solution as it’s labelled) which I use is 33.5% concentration. I
only use about a capful in one litre of water (and it sure takes my
breath away when I take the lid off). It’s probable that the stuff
sold in grocery stores is way more diluted than 33.5%, hence why you
need to use so much of it.
So, to realistically compare with each other what strength you use,
people need to state the concentration (probably stated in terms of
a percentage), and how much they use of that to how much water. Then
we’re all on a level playing field.
The formula for this sort of problem is:
Original Concentration X Original Volume = Final Concentration X
Final Volume
We are trying to find out the Final Concentration.
So to substitute my figures, I use approx 40ml (0.04 litres) of
33.5% ammonium hydroxide (ammonia solution) added to 1 litre of
water, so:
Orig. Conc. X Orig. Vol. = Final Conc. X Final Vol.
33.5 X 0.04 = Final Conc. X 1.04 (1 litre plus 0.04 litres)
Final Conc. = (33.5 X 0.04) / 1.04
Final Conc. = 1.34/1.04
The Final Concentration of my solution is approximately 1.29%.
Now, I don’t know the concentration of the solution you are buying
in the States, but I just found a website selling 8% solution, so as
an example, using your proportions (and using the example of 200ml
ammonia solution to 100ml water) and 8% solution, here goes:
Orig. Conc. X Orig. Vol. = Final Conc. X Final Vol.
8 X 200 = Final Conc. X 300 (200ml + 100ml)
Final Conc. = (8 X 200)/300
Final Conc. = 1600/ 300
Final Concentration in this example is 5.33%. If my guess work
regarding the concentration of solution available for purchase is
correct, then as you can see your solution is still quite a bit more
concentrated than what I am using. I am, however, not taking in
repairs or jewellery for cleaning on a regular basis so perhaps your
concentration may be more suited to the task.
It’s important to note that the above formula can be used to make a
solution of a desired concentration (Final Concentration in the
formula), by rearranging the formula and knowing what concentration
of solution you are starting with. It will tell you what volume of
that solution you need to add. So, if for example you wanted to end
up with 1 litre of solution, substitute your concentration of
purchased solution (ie 8% in my second example) into the Original
Conc. part, the desired Final Concentration and 1 litre for the Final
Volume. It will tell you how much to add. This volume must be
subtracted from the final volume of 1 litre so you’ll be adding X
amount less than 1 litre of water. Is that understandable? This will
be useful if someone comes up with the optimum concentration needed
to clean the scum off diamonds.
So, as you can see, just stating volumes used is not informative
enough to make comparisons with each other. If folks who buy the
ammonia solution can state what concentration they buy, how much
they use and how much water, we can more easily compare the
concentrations of the solutions being made.
Sorry for being boring or nit-picking again.
Helen
UK