chemistry question

Originally posted by sonhouse
Not sure about the technology of the 20 dollar variety but the good ones use a permeable glass covering over a metal electrode affair and if it is allowed to get dry, solids condense out in the little openings in the glass and stops ion flow and that stops Ph readings. So they need to be kept in liquid, preferably DI water, or distilled if you don't have DI around.

That would make sense. I have loads of DI around gallons and gallons of the stuff. It goes through a mixed bed resin and comes out measurable in parts per millionth, you can get water down to zero parts per millionth ) is this a measurement of salinity? ) I always wondered if distilled water and DI water were the same thing.

Originally posted by robbie carrobie
That would make sense. I have loads of DI around gallons and gallons of the stuff. It goes through a mixed bed resin and comes out measurable in parts per millionth, you can get water down to zero parts per millionth ) is this a measurement of salinity? ) I always wondered if distilled water and DI water were the same thing.

Distilled water still has contaminants in it and the measure is called 'ohms per square Cm' which is a standard for the measure of water. Distilled water clocks in at about 25000 ohms/square which, when you invert that number it comes out in Siemens, here is the definition, just the invert of ohms:

https://en.wikipedia.org/wiki/Siemens_(unit)

So the unit of one microsiemen is one megohm, one million ohms.

In micro-siemens, 25000 ohms = 40 microsiemens.

The best you can get in terms of conduction of ultra pure water is about 18 megohms. That clocks in at 0.0555 microsiemens (18 million inverted)

That shows distilled water conducts electricity about 700 times greater that real DI water.

That is an indication of conductive contaminants still hanging around in distilled water which takes a few more steps of purification to get it to the max of 18 megs. Reverse osmosis for instance, and the resin beds you talked about.

What do you use DI water for?

The problem with DI water is the water molecule is polar, if you remember the mickey mouse ear diagram where you have an oxygen atom and the 2 hydrogen atoms sit at about 108 degree angle which means one end of the water molecule has a plus charge and the other end a minus charge.

http://witcombe.sbc.edu/water/chemistrystructure.html

The result is if DI water comes in contact with metals, it rips off bits of the surface of the metal and eats away the metal until the water is no longer DI but something like distilled or worse.

You can't use metal pipes like copper or stainless with DI water flowing in it, you can only use PVC or teflon, some plastic that resists the polar effect of DI water. That is the only way you can keep DI water DI. BTW, DI stands for 'De-Ionized'.

Originally posted by robbie carrobie
Ok I'll tell you.

During the process of brewing malted grain is immersed in water. The water is heated to a temperature usually between 64 and 70 Celsius. 66 is considered optimal for enzymatic activity in which the enzymes alpha and beta amylase covert starches into fermentable and not so fermentable sugars. This process of conversion is not o ...[text shortened]... hes in malted grains to fermentable and not so fermentable sugars. Now I think I understand it.

This link could help
http://www.thehomebrewforum.co.uk/showthread.php?t=57324

Originally posted by joe shmo
Why the acronym? If your annoyed by the question, just ignore it. Picking on people for using the collective intellect of the science forums to discuss and expand their horizons is counter productive to the cause.

Because there are such things as stupid questions.

The one in the OP qualifies.

As twhitehead pointed out what RC wanted to know was entirely unclear.
What he actually asked for was answered by my post.

What he wanted was made clearer by his subsequent post where he bothered to actually explain
what he was asking.

If he had opened with that, he wouldn't have got a snarky response [from me at least].

Originally posted by sonhouse
Distilled water still has contaminants in it and the measure is called 'ohms per square Cm' which is a standard for the measure of water. Distilled water clocks in at about 25000 ohms/square which, when you invert that number it comes out in Siemens, here is the definition, just the invert of ohms:

https://en.wikipedia.org/wiki/Siemens_(unit)

So the u ...[text shortened]... ect of DI water. That is the only way you can keep DI water DI. BTW, DI stands for 'De-Ionized'.

Yes I understand what DI stands for thanks. I use it in my business for cleaning. So its seems that basically what you are measuring is the conductivity of water? I have a little TDS meter that I use to test the water and it gives me a reading in parts per millionth.

Originally posted by googlefudge
Because there are such things as stupid questions.

The one in the OP qualifies.

As twhitehead pointed out what RC wanted to know was entirely unclear.
What he actually asked for was answered by my post.

What he wanted was made clearer by his subsequent post where he bothered to actually explain
what he was asking.

If he had opened with that, he wouldn't have got a snarky response [from me at least].

You have contributed nothing to anyones understanding here and you were rightly called out for behaving like a juvenile delinquent and NO you answered nothing. I did not need to know what calcium carbonate was or any of the other elements, i did not ask what calcium carbonate was. What i wanted to know was how they (calcium carbonate, sulfate, chloride etc) differ from each other and more importantly how they interact with one another under certain circumstances. Your information was useless and was the equivalent of providing a lexical definition when you were asked to comment on some type of idiomatic clause, practically useless. But its ok i managed to work the matter out for myself and you have the unenviable accolade of having contributed nothing to anyones understanding, well gee thanks for nothing.

Originally posted by robbie carrobie
Yes I understand what DI stands for thanks. I use it in my business for cleaning. So its seems that basically what you are measuring is the conductivity of water? I have a little TDS meter that I use to test the water and it gives me a reading in parts per millionth.

TDS= 'Total Dissolved Solids' and they just calibrate a resistance reading into parts per million of dissolved solids. It is still a resistivity measurement. If you use DI water in your business you might be interested in one meter we use, from Myron L comapany, called the EP meter,
Myron L Conductivity meter model EP. battery powered,
WWW.myronl.com

They are in my old stomping grounds, Carlsbad Ca. 2450 Impala Drive 92010

Don't know how much you can afford but this little baby is under $500, 400 comes to mind.

Might be worth it to keep tabs on your DI and distilled water.

I see their phone number is 760 438 2021. Plus whatever country code you need but the web would be where you order one anyway.

Just a thought.

How it is used, you first rinse out the little cup shaped opening on top 3 times then put in your water to be measured and this model has 4 multiplier settings, 0.1 siemens, 1 s., 10, 100 and 1000. The 0.1 gives you the ability to read the best DI water, 18 megs, directly. labled 0 to 5 micromhos (microseimens)/Cm. plus a direct ohms reading in the 0.1 position.

It is a down and dirty quick way to test your water. Tap water pegs the meter🙂

Our DI water system has its own Siemens meter and such but our hand held unit can test as a reality check the DI water taps in our cleanroom.

It proved itself last week, Our DI taps measured about 1 megohm instead of 18 as it should have been and we found a bad valve in the DI water RO filter area, the company who installed it came out and replaced the valve and the DI system is as good as new now.

Well, it IS new but what the hell....

What kind of service or product do you make in your business that requires DI water? It's pretty corrosive when it comes into contact with most any metal.

And I suppose you know not to drink DI water, right?

Its not exactly poisonous but it will upset your electrolytes.

Originally posted by sonhouse
TDS= 'Total Dissolved Solids' and they just calibrate a resistance reading into parts per million of dissolved solids. It is still a resistivity measurement. If you use DI water in your business you might be interested in one meter we use, from Myron L comapany, called the EP meter,
Myron L Conductivity meter model EP. battery powered,
WWW.myronl.com
...[text shortened]... not to drink DI water, right?

Its not exactly poisonous but it will upset your electrolytes.

I sometimes spray it on myself in summer time if it gets really really hot although the relief is only for a few moments and then it gets worse. What happens if I drink it?

Originally posted by robbie carrobie
You have contributed nothing to anyones understanding here and you were rightly called out for behaving like a juvenile delinquent and NO you answered nothing. I did not need to know what calcium carbonate was or any of the other elements, i did not ask what calcium carbonate was. What i wanted to know was how they (calcium carbonate, sulfate, chlor ...[text shortened]... le accolade of having contributed nothing to anyones understanding, well gee thanks for nothing.

You have contributed nothing to anyones understanding here and you were rightly called out for behaving like a juvenile delinquent

Only in your little deranged mind.

Which brings me to the other reason I have no qualms about snarkiness towards you.
You're a science denying ignorant blow-hard with delusions of grandeur.

I would also point out that learning how to research basic facts yourself is a more useful lesson than just being
spoon fed the facts, and this showing where the information you asked for could be found and how to find it was
in and of itself helpful.

NO you answered nothing

You asked, and I quote "What is the difference between carbonate and bicarbonate."

The difference is that they are difference chemicals, which I demonstrated by posting their chemical formulas
and links to more detailed descriptions about them.

I thus answered the question you actually asked.

If you wanted to know something different, you should have asked a different question.

I did not need to know what calcium carbonate was or any of the other elements, i did not ask what calcium carbonate was. What i wanted to know was how they (calcium carbonate, sulfate, chloride etc) differ from each other and more importantly how they interact with one another under certain circumstances. Your information was useless and was the equivalent of providing a lexical definition when you were asked to comment on some type of idiomatic clause, practically useless.

Perhaps you can learn yet another lesson from this in that it might teach you to take the time to make clear
what question you are asking rather than hope that the people you are asking to help you are mind readers.

You might have noted that you received a bunch of [possibly] helpful contributions from people once you
made what you were asking clear.

But its ok i managed to work the matter out for myself and you have the unenviable accolade of having contributed nothing to anyones understanding, well gee thanks for nothing.

Ahh, well, apparently as ever, you learned nothing.

Originally posted by googlefudge

You have contributed nothing to anyones understanding here and you were rightly called out for behaving like a juvenile delinquent

Only in your little deranged mind.

Which brings me to the other reason I have no qualms about snarkiness towards you.
You're a science denying ignorant blow-hard with delusions of grandeur.

I would al ...[text shortened]... ing, well gee thanks for nothing.[/quote]

Ahh, well, apparently as ever, you learned nothing.

Take it to the bitchin forum Googlelord, this is science. You have contributed nothing and by contrast every sonhouse post I am learning something new. I worked out for myself what I needed to know without a single iota from you, panic over! problem solved! Now either pony up something that we can learn from or bitch to someone that cares.

Originally posted by robbie carrobie
Take it to the bitchin forum Googlelord, this is science. You have contributed nothing and by contrast every sonhouse post I am learning something new. I worked out for myself what I needed to know without a single iota from you, panic over! problem solved! Now either pony up something that we can learn from or bitch to someone that cares.

Why should I take the time to help YOU?

Originally posted by sonhouse
Distilled water still has contaminants in it and the measure is called 'ohms per square Cm' which is a standard for the measure of water. Distilled water clocks in at about 25000 ohms/square which, when you invert that number it comes out in Siemens, here is the definition, just the invert of ohms:

https://en.wikipedia.org/wiki/Siemens_(unit)

So the u ...[text shortened]... ect of DI water. That is the only way you can keep DI water DI. BTW, DI stands for 'De-Ionized'.

For clarity, in your first paragraph you have a measure of the purity of water which is it's resistivity. You then state that "if one inverts that number it comes out in Siemens.". If one inverts resistivity one obtains a meaningless number measured in units of m^2/Siemen. Conductance, the quantity measured in Siemens, is the inverse of resistance, measured in ohms. You probably meant that, but it wasn't what you wrote.

Originally posted by robbie carrobie
Ok I'll tell you.

During the process of brewing malted grain is immersed in water. The water is heated to a temperature usually between 64 and 70 Celsius. 66 is considered optimal for enzymatic activity in which the enzymes alpha and beta amylase covert starches into fermentable and not so fermentable sugars. This process of conversion is not o ...[text shortened]... hes in malted grains to fermentable and not so fermentable sugars. Now I think I understand it.

All I know about this is poorly remembered A'level Chemistry. I remember the words "buffer solution" and you might want to look that up.

I think the underlying thing is that in solution the calcium salts turn into calcium ions (alkali) and sulphate/chloride/carbonate ions (acid). Sulphate and choride are strong acids but carbonate is a weak one, so adding calcium carbonate to your calcium sulphate or calcium chloride solution will tend to increase the pH as there is the same pH increasing effect from the calcium ions in calcium carbonate as in Calcium chloride or calcium sulphate but there is less of a pH decreasing effect from the carbonate ions as from chloride or sulphate ions.

Originally posted by DeepThought
All I know about this is poorly remembered A'level Chemistry. I remember the words "buffer solution" and you might want to look that up.

I think the underlying thing is that in solution the calcium salts turn into calcium ions (alkali) and sulphate/chloride/carbonate ions (acid). Sulphate and choride are strong acids but carbonate is a weak one, so ...[text shortened]... ere is less of a pH decreasing effect from the carbonate ions as from chloride or sulphate ions.

thanks man, yes that was the crux of the matter, now resolved 😀

Here is something that remains unresolved

the terms carbonate and bicarbonate are used somewhat interchangeably; they are similar but not quite the same thing. For now , it is probably sufficient to regard calcium bicarbonate as the water soluble form of calcium carbonate (chalk) Calcium carbonate does not dissolve much in water, so from our point of view it exists in its bicarbonate form in water - Graham wheeler - Brew your own real British ale, page 50.

This is still a matter of some confusion.

Originally posted by robbie carrobie
I sometimes spray it on myself in summer time if it gets really really hot although the relief is only for a few moments and then it gets worse. What happens if I drink it?

Here is a link to some people answering that question, the gist is DI water is an aggressive solvent and can strip electrolytes from your body because of the polar nature of the purest water. Obviously a couple liters won't hurt you but if you continue day after day, effects will be seen in bloodwork.

http://www.finishing.com/110/17.shtml