Sciencemadness Discussion Board

Concentrations of a few "Household" Chemicals

hodges - 18-12-2003 at 18:12

I recently decided to check the concentration of a few "household" chemicals that I use for experiments.

"Rooto Professional Drain Opener": This contains concentrated sulphuric acid. It is noticably heavy for a container of liquid its size, showing the high density of the H2SO4. This product has a very light yellow color and the consistency of thin motor oil. This would imply a strength of around 18M. For experimenting, I use a diluted version made from 5 parts water and and 1 part product. I have always assumed this to be a 3M solution of H2SO4. So to test, I used NaHCO3 (baking soda). The neutralization reaction I assume is as follows -
2NaHCO3 + H2SO4 --> Na2SO4 + 2H2O + 2CO2
I decided to neutralize 0.05 moles of Na2SO4. I calculated this to be 4.2 grams. Assuming that the H2SO4 is 3M, I calculated that it would take 8.2ml to neutralize it. I mixed the NaHCO3 with enough water to dissolve it and slowly added the H2SO4. I found that after adding around 7.5ml, the production of CO2 decreased markedly as more H2SO4 was added. I added a touch more NaHCO3 and obtained more fizzing - then when I added more H2SO4 the fizzing was more vigerous. So I believe 7.5ml to be the approximate completion point. This is pretty close to the 8.2ml I had calculated, and the difference could easily have been an error in weighing (I used a postal scale). Thus I conclude that the Rooto product is around 18M strength.

With my H2SO4 solution verified to be close to 3M, I was able to do a rough titration using an indicator and determine the approximate strengths of two other household chemicals in a similar manner. For "HomeBest Clear Ammonia" I calculated around 1.5M NH4OH.

Being unable to find HCl, which I bought as "muriatic acid" 25 years ago, and having had good luck with the Rooto drain cleaner, I bought some "Rooto Toilet Bowl Delimer/Cleaner". This had a large "Danger!" label and says it contains hydrochloric acid. But as soon as I opened it, I realized it sucked. When shaken, what appeared to be soap bubbles (!) formed. In addition, the liquid is a dark brown and has a nasty cleaning odor which is not like the HCl I was used to. I remember I used to put a bit of muriatic acid in a bowl and place it beside a bowl of household ammonia to form clouds of white NH4Cl. When I tried this with the Rooto product, I got just a faint trace of NH4Cl in the air nearby, indicating a much weaker solution. By titrating, I determined a concentration of only 4M HCl (I think muriatic acid is something like 12M).

As a sanity check, I noted how fast the two acids react with some zinc metal from an old (non-alkaline) dry cell. A drop of either the 3M H2SO4 or the 4M HCl produced a coating of bubbles on the Zn, but definitely not a vigerous reaction. I believe this would be typical because I remember the reaction between muriatic acid (assumed 12M HCl) and zinc was only of moderate speed (unlike the reaction with Al foil, which was fast enough to heat the solution to boiling, evolving much HCl gas in addition to H2 and resulting in unsuccessful attempt to make a lighter-than-air balloon back when I was in high school).

Anyway, I am curious if my calculations and observations sound reasonable, and if anyone else has ever tested the strengths of other "household" chemicals.

Hodges

Mumbles - 18-12-2003 at 20:21

The slightly lower than theoretical result of the Sulfuric Acid, is probably not entirely experimental error. Its not 98%, but it is close. I believe it is something like 92 or 93%. Another possible source of error is the miscalculation of density because of the slightly lower concentration.

[Edited on 12-19-2003 by Mumbles]

Rooto sulfuric acid strength

Magpie - 23-12-2009 at 16:05

A member has asked me how I arrived at my value of 96wt% for Rooto sulfuric acid.

In 2006 I titrated some 0.188N NaOH using a potassium acid phthalate standard I had weighed out (0.171 N). Using the standardized NaOH I titrated some diluted Rooto sulfuric acid (0.182 N). The results indicated the normality of the Rooto to be 35.8N, or 17.9M. This is equivalent to 95.75wt%, assuming a sp gr of 1.835 per my Lange's handbook.

It would be interesting to know what strength others have found for their Rooto sulfuric acid, a drain cleaner.

[Edited on 24-12-2009 by Magpie]

entropy51 - 23-12-2009 at 16:48

2009 was a good vintage for Rooto

My first post on Science Madness:
Quote: Originally posted by entropy51  
Please excuse any hiccups as I try my first post.

I have had good luck buying Rooto in the past; it was never very discolored and has worked well for my purposes.

I just bought a new bottle and have made two surprising observations. The first is that this bottle is very nearly colorless. It has only the very slightest brownish tint, almost identical to reagent grade sulfuric.

The more surprising thing is that when a 1 mL sample was diluted 1:100 and an aliquot titrated with 0.095 N NaOH, it appears that the Rooto is about 97% H2SO4. Since this seemed rather high (titrations of previous bottles were about 93%), I made a 1:00 dilution of reagent grade acid and titrated with the same NaOH, obtaining a very similar result as the Rooto titration.

I realize that many impurities may be lurking in this material, but judging by color and concentration it appears to be significantly better than any Rooto I've used in the past.

I'm curious as to whether others have noticed similar changes in the material sold in Root bottles?
So I found something like 97%, same as Magpie's, within experimental error. And it's not black, or even dark brown.

Picric-A - 23-12-2009 at 17:54

The Drain unblocker we buy in the UK ( i buy from Wilkinsons) has written on the label itself "95% Sulphuric acid Minimum". I am not sure whether this means 95% of the product is H2SO4 or the Sulphuric acid is 95% conc, tbh i dont realy care, it gets the job done for things where i dont need A.R or L.G acid.

grndpndr - 24-12-2009 at 05:01

I very carelessly misread my drain cleaner as liquid lightning
which I also took to be the red label variety of only 44% with a reputation for being very poor acid with very many additives.
Upon having a look its actualy liquid fire a much better acid by reputation far over %90 purity with a light motor oil color-viscosity.Should be @%9 liter.Cheaper yet was the 35% battery electrolyte 6liters for $14.A bit less than $7 L once concentrated to 98% approx 2.2L of near water white 98%
H2SO4 with minimal additives or impurities which could 'poison' the battery.
EBay also has 'new' distributor(dowless123)IIRC, with a variety of tech/reagent grade chems,the nitrates in particular catcing my attention,KNO3 6lbs $21 included shipping which was $11 to my home,7.5lbs $24 shipping also included up to
25lbs and 50lbs.NaNO3 10lbs shipping included @ $28.All at least tech grade crystaline chemical of 99%+

sonogashira - 29-12-2009 at 10:07

Quote: Originally posted by Picric-A  
The Drain unblocker we buy in the UK ( i buy from Wilkinsons) has written on the label itself "95% Sulphuric acid Minimum". I am not sure whether this means 95% of the product is H2SO4 or the Sulphuric acid is 95% conc, tbh i dont realy care, it gets the job done for things where i dont need A.R or L.G acid.

Anyone know the brand name of this product?- I have never seen it (only sodium-hyroxide based)

DJF90 - 29-12-2009 at 10:30

Sonogashira: Go to pretty much any hardware store in the UK (Focus, B&Q, Homebase, Robert Dyas) and you will always find sodium hydroxide, in very pure form, generally as prills. The bottle I have is called "Caustic Soda" and unimaginatively it is just that; 98% Sodium hydroxide pearl.

sonogashira - 29-12-2009 at 10:52

^ It was the sulphuric acid I was asking about :P A lot of caustic soda your right, but suplhuric acid I see rarely (maybe not in every store?)

Picric-A - 29-12-2009 at 12:41

Sorry i cant remember, it is sold in big orange bottles with Drain unblocker on. On the reverse of the bottle there is a huge corrosive sign with Contains 95% H2SO4 on it.
Havnt bought this stuff in a while and am away form my lab so i cant tell you at this moment.

Picric-A - 29-12-2009 at 12:42

Found a picture of it just searching the web :p
It comes in large and small bottles.

H2SO4.jpg - 1kB

DJF90 - 29-12-2009 at 14:07

Ooops sorry Sonogashira. Robert Dyas has been the best OTC source I seen so far, and they stock several different brands, ranging from 93-98% if memory serves...

sonogashira - 29-12-2009 at 16:18

Don't think I have ever seen a robert dyas shop :( Maybe I will look in a larger wilkinson store because I'm sure it wasn't in the one I visited... Did get citric acid though!

Thank you

[Edited on 30-12-2009 by sonogashira]

smuv - 18-4-2011 at 13:48

I am resurecting this thread, because while googling for a rooto msds (their blue ribbon ammonia, anyone able to find this or any of their msds's?) I came across something interesting about their sulfuric acid.

Back in the late 80's the rooto corp was cited by the EPA for not reporting that they were processing chemicals in their facility. Rooto corp, argued that they were not subject to such reporting as they were not processing chemicals, they were simply repackaging them.

Quote:
Respondent argued that it did not process the two chemicals
so as to be subject to Section 313's reporting requirements
because "the sulfuric acid and hydrochloric acid which came into
Rooto's facility were identical to the chemicals which left
Rooto's facility. "


Though an old piece of evidence, it does indicate something I have long suspected, rooto is simply re-pack operation; the products they sell are just tech grade chems in smaller bottles.

Source: http://www.epa.gov/oalj/orders/1995/rooto-corp-epcra-102595....


BTW: Rooto was fined over a $100k in 1991 b/c of this, repackaging is processing under EPA rules.

Ephoton - 18-4-2011 at 19:57

some of the densities of drain cleaning H2SO4 are not only based on the acid content.

they often have carbon in them as a color adative so often a hyrgometer will not tell you
concentration.

as you did smuv titration realy is the only way to tell.

quicksilver - 19-4-2011 at 08:14

Entropy51's comment of "2009 being a good year for H2SO4" is actually very insightful as most all sulfuric acids sold as drain cleaners are bought from other industrial concerns (often anodizing) and vary quite often! A single brand name actually does NOT mean that the material will maintain a purity or strength level for one period of time to the next. H2SO4 is perhaps the most commonly produced non-mined chemical in the world and more often than not is recycled if not used in a manner that destroys it or exposes it to explosives or radioactivity. Frequently discoloration of a blackened sort (especially if a granular material is also found) imply that it was used in a metal-treatment format. This is often the most easily recovered, recycled usage. Applying heat (60-70C) will bring about not only a strengthening of the acid but any solids will begin to sink and cling together for easy removal through decantation or filtering; this may also bring about removal of discoloration. But a brand-name per se' guarantees very little as most all drain acids are surplus.

smuv - 19-4-2011 at 09:27

Well, if by recycled you mean distilled and recovered, sure that sounds reasonable, but if you mean they just filtered and concentrated the acid, I don't think so.

In this case rooto tried to argue a few things to get out of paying the non-reporting fine. One of the things was that in ~1990 a few years after the incidents in question but before the EPA started motions, the law was changed and sites processing H2SO4 did not have to report processing it. So rooto argued that they did not have to report because they were processing H2SO4. Simply put, if they were dealing with anodizing or pickling waste they would not have been able to make that argument.

Also, it seems illogical that a product containing significant metal salts would be allowed to be poured down the drain.

So ya I agree, everything is recycled in the chemical industry. But if it is distilled, well IMO thats just tech sulfuric acid, but if you just mean filtered, cocentated or other method which would leave very impure acid, I doubt that until you provide a source or some compelling evidence.