[Ian_Giles]

Some humorous replies....too many of them.

In moderator mode I'll not remove them, if only to highlight why they DO get removed.

Once a humorous quip is posted others follow suit, the thread then becomes pointless.


The thrust of this thread is good, much is said about pure water, but little is proved, apart from it's cleaning capabilities of course.

Pure water DOES become acidic! It turns into carbonic acid!!!
This is because it absorbs carbon dioxide from the atmosphere, and apparently there is scientific proof for this, I've read it but I'm blowed if I can remember where it was
But we are not talking anything remotely major of course, it is barely measurable...with litmus paper it will show up as PH neutral, - I believe - but it has a good effect on kids when they are putting their grubby paws on glass you have just cleaned, or they are getting in the way of you working, tell them to watch out because it's carbonic acid gives them pause for thought!

Simon did his own experiment, I think I might do one of my own!
I think I'll T-cut the bonnet on my van and use a non silicone polish on it, then wash one half with tap water, and the other half with pure water and see if I can spot a difference....
Not very scientific I suppose, but I'd be interested to see if there really is a difference between the two halves of the bonnet.

Ian

[Pj]

Lets rule out one saying: "Water wants to return to its normal state"
What is "normal" for water?  Water simply has the capability of eroding mainly due to force/pressure as with tides, dripping onto stones etc.  Water also has the capcity to absorb and disolve all manner of materials and minerals.  But impure water is not it's "normal" state.

[matt]

So if pure water is not aggrssive...why has most of WFP user speed lined there vans!!!

because any water will rot your van floor

[[GQC] Tim]

Water is called the universal solvent. Some digging, still can't grasp the concept of why pure water cleans better then normal water, but I think it's all down to not being saturated already with minerals and salts etc.

pH values

The theoretical pH of highly purifed water is 7.0. In practice, however, most purified water will have a pH that is slightly acidic (less than 7.0) due to the presence of dissolved carbon dioxide (CO2) from the atmosphere. Dissolved carbon dioxide reacts slowly with water to give the bicarbonate and hydronium ions.

    CO2 (g) + 2H2O(l) ⇋ HCO3- + H3O+

Note that carbonic acid, H2CO3, is only formed in strongly acid solutions. Distillation temporarily removes dissolved CO2 from the water. However, during condensation the water reabsorbs CO2 again resulting in a pH that is less than 7.0.

http://en.wikipedia.org/wiki/Distilled_water

"I've heard that I shouldn't use copper pipes with any/all brand/s of RO system/s?"

Most brands of RO system will reduce at least 85-90% of salts in water, so you can assume the water salts concentration would be about 1/9th of the content in the feed water. The aggressiveness of this purified water towards the materials into which it comes in contact is a function of its purity. The better the purity, the more its aggressiveness. Piping after an RO unit should therefore always be non-metallic. RO units will pass all the CO2 that is in the feed water. This means the water will be more corrosive. Don't use copper piping after any (brand of) RO system.

Water is the universal solvent.  Even as it falls to earth as rain it picks up particles and minerals in the air.  And as soon as it hits the ground it captures minerals from the soil and rock upon which it lands.  It makes its way into streams and rivers, carrying soil from the mountains to the sea.

Nowadays water picks up contaminants such as airborne mercury while it’s falling as rain. 

http://www.cleanairpurewater.com/pure_water.html

Why is water such a good solvent?

Water is a good solvent due to its polarity. The solvent properties of water are vital in biology, because many biochemical reactions take place only within aqueous solutions

http://www.edinformatics.com/interactive_molecules/water.htm

    * Water is a very strong solvent, referred to as the universal solvent, dissolving many types of substances. Substances that will mix well and dissolve in water, e.g. salts, sugars, acids, alkalis, and some gases: especially oxygen, carbon dioxide (carbonation), are known as "hydrophilic" (water-loving) substances, while those that do not mix well with water (e.g. fats and oils), are known as "hydrophobic" (water-fearing) substances.

    * All the major components in cells (proteins, DNA and polysaccharides) are also dissolved in water.

http://en.wikipedia.org/wiki/Water

[[GQC] Tim]

Water is called the "universal solvent" because it dissolves more substances than any other liquid. This means that wherever water goes, either through the ground or through our bodies, it takes along valuable chemicals, minerals, and nutrients.

http://ga.water.usgs.gov/edu/waterproperties.html

Question -  Why is water a good solvent?

You are right, water is an excellent solvent. Although not all things
dissolve in water, it is often referred to as the "Universal Solvent". The
geometry or the structure of the water molecule is what makes is so good. In
compounds, the number of positive protons is equal to the number of negative
electrons, so it would appear that all compounds are electrically neutral.
But that is not the case. Water's geometry is such that the electrons are not
uniformly distributed throughout the molecule. So the end of the molecule
with greater electron density is slightly negative and the other slightly
positive. Water and compounds like it are said to be polar, and kind of
behave like a magnet. Water generally dissolves other substances that are
also polar, but not non-polar substances like oil. (To continue the magnet
analogy, magnet are not attracted to nonferrous metals like aluminum.) Water
is quite polar which explains many of its properties like its high melting
and boiling points, high surface tension, and why it expands when frozen. To
see for yourself, get a thin stream of water flowing from a faucet. Using a
piece of wool or silk, build up a static charge on a plastic comb by rubbing
the fabric briskly across the comb. Bring the comb near the stream of water.
The charged comb will actually deflect the stream of water!
Many non-polar substances are made soluble in water by use of detergents
and soaps, both of which are large molecule with a polar end and a non-polar
end. The polar end is attracted to the polar water molecule, and the
non-polar part to the non-polar greasy dirt.

http://www.newton.dep.anl.gov/askasci/chem00/chem00045.htm


Another interesting bit of why we use soap

"Cleaning Up" with "Electric Water"

So, water is the most universal solvent we know about, and we have a flower vase to clean up. Lots of hard mineral stuff on its sides. So we get some "pure water" and scrub and scrub. We can see that it is working, but it is taking too long and using too much "pure water". So, what is the first thing we think of doing ? ...

We Add SOAP !!!

What does the soap do? – It makes the water wetter. – How can wet water get wetter?

We add something to the water that changes the electrical properties of the solution, which then makes it easier for the water molecules to wiggle their way between the unwanted "dirt particles".   Adding a surfactant (a surface-active agent) such as detergent can decrease surface tension, but this will not increase water's carrying capacity unless it changes the basic colloidal chemistry of the liquid by adding a material with negative ions.

Link to ... Looking at a water molecule Soap works by breaking up the electric field which creates surface tension. This allows water to "surround its victim and carry it away".

This works fine if your dirt isn't stuck to securely to your surface.
But what if it is "well bonded" and sticks to itself really well, like the minerals on the sides of your vase?

Water's weak electric charge will get the job done if you have enough "pure water" and enough time. But what if you can't use soap, or you want to use less water and less time?     You then bring in the ...
Anions( – )   and   Cations( + )
! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

Here is a case where the classic notation inhibits the understanding of the subject.

The reason atoms form chemical bonds has more to do with mechanics than it does with electricity. Hydrogen's positive notation when classed as a Cation, is not because it has two positrons and only one electron — hydrogen has only one positron in its nucleus — it is because with only one electron in orbit, it wobbles all over the place and atoms have a strong desire not to — Inertia you know.

The nature of hydrogen's electron orbit makes it a perfect candidate to receive an additional electron (if the spin is right) to achieve dynamic balance for the hydrogen's atomic system. Because it can receive an electron it is considered to be a positive entity and is called a Cation. (Electropositive)

On the other side of the binary is the Anion. Chlorine is classed as an Anion. Chlorine has an electron in a somewhat unstable orbit that it would love to share. Since it is providing the electron, it is classed as an Anion. (Electronegitive)

When Hydrogen and Chlorine get together, they share the electron in a figure 8 orbital that allows them to achieve a symbiotic dynamic stability.

Hydrochloric acid ( H+Cl– ), is what our bodies produce to electrify our stomach fluids. But pure HCl can't do the job by itself.

In order to achieve good dynamic stability, the hydrogen atom and chlorine atom cuddle up real close. It takes water to intervene in this relationship, to allow the electric force to manifest and do its work. The water molecules cuddle up to the hydrogen and chlorine atoms, like so many children wanting to get in on their parent's hugs.

WOW !

So, what about the Flower Vase !

Adding a little HCl (or vinegar) to the pure water in your vase will activate the water's electrical potential giving the solution the power to unlock the atomic bonds that are holding the minerals to the side of your vase.

Result   ——   A Clean Flower Vase !!!

[frames to panes]

Too much for me! I thought the cleaning was done by the brush and the debris was simply washed away by the pure water. In my opinion there is nothing particularly scientific about it at all. 

[dd]

According to Aquafactors (Tucker Pole), D.I water reaches a ph of between 
5.5-6.  7 is neutral, so it is slightly acidic. The explanation is that everything is processed out, including alkalinity and CO2. It then absorbs CO2 from the atmosphere but without the alkalinity to buffer it it becomes acidic.

Heating the water: every 10 degree rise in temperature doubles the potency of the CO2.

In my experience pure water is more aggressive and would expect heated pure water to be more so.

 

[Sir Squeaky]

 :

[Neil Williams]

It then absorbs CO2 from the atmosphere but without the alkalinity to buffer it it becomes acidic.

Global warming is so they tell us a result of increased CO2.
So using WFP means we are saving the planet as pure water absorbs CO2  .... Pure brilliance 
Something to throw at the water companies when they next try to stop us working.
Just call me a Genius

[Nathanael Jones]

But DOES PURE WATER REALLY CLEAN BETTER???

it dries better,... but does it actually remove more dirt than standard water? It probably does to a microscopic degree, but I doubt its enough to make a difference in the real world.

It's the drying that makes us think its working really well,.. but the fact that it simply lacks dissolved impurities doesn't make it "aggressive". And a very slight difference in PH has been shown,... but acid rain can have a lot worse PH than that!

[SherwoodCleaningSe]

According to Aquafactors (Tucker Pole), D.I water reaches a ph of between 
5.5-6.  7 is neutral, so it is slightly acidic. The explanation is that everything is processed out, including alkalinity and CO2. It then absorbs CO2 from the atmosphere but without the alkalinity to buffer it it becomes acidic.

Heating the water: every 10 degree rise in temperature doubles the potency of the CO2.

In my experience pure water is more aggressive and would expect heated pure water to be more so.

 

I read that info from tucker, but from my little experiment I would say they were inflating the figurers a little bit, I'd say the ph of warm pure water is more like 6.7.  May be it could get a lot lower if you had it hot say 65C.  Tucker though are trying to dis other products to sell their soap dispenser, so I wouldn't believe them 100%.

As for pee, I would have never got it in the tube, not without getting my hands wet.

Simon.