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chemistry question

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rc

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What is the difference between carbonate and bicarbonate. What is the difference between chalk and gypsum for they appear to me to be one and the same thing.

Its ok I think I have partly found the answer. Calcium carbonate (chalk) is an alkali. Calcium sulphate (gypsum) is acidic.

googlefudge

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LMGTFY

Bicarbonate formula HCO3-
Carbonate formula CO3--
Gypsum CaSO4·2H2O
Chalk [main component] CaCO3

https://en.wikipedia.org/wiki/Bicarbonate
https://en.wikipedia.org/wiki/Carbonate
https://en.wikipedia.org/wiki/Chalk
https://en.wikipedia.org/wiki/Gypsum

rc

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Originally posted by googlefudge
LMGTFY

Bicarbonate formula HCO3-
Carbonate formula CO3--
Gypsum CaSO4·2H2O
Chalk [main component] CaCO3

https://en.wikipedia.org/wiki/Bicarbonate
https://en.wikipedia.org/wiki/Carbonate
https://en.wikipedia.org/wiki/Chalk
https://en.wikipedia.org/wiki/Gypsum
this does not answer the question, if I wanted their definitions I could have simply done the same as you have. I need to understand their relationship to each other. Did I not make that clear?

twhitehead

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Originally posted by robbie carrobie
I need to understand their relationship to each other.
They both contain Calcium, Carbon and Oxygen atoms. What other relationships are you looking for?

Did I not make that clear?
No, not really. It is not at all clear what you would like to know. I am sure the Wikipedia pages will tell you about the various properties of both.
They are both white and powdery, but then almost all salts are. (when not in large crystals)

rc

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Originally posted by twhitehead
They both contain Calcium, Carbon and Oxygen atoms. What other relationships are you looking for?

[b]Did I not make that clear?

No, not really. It is not at all clear what you would like to know. I am sure the Wikipedia pages will tell you about the various properties of both.
They are both white and powdery, but then almost all salts are. (when not in large crystals)[/b]
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 only dependent upon temperature but the relative PH of the water, a PH of 5.3 being considered optimal. Now the PH of the water is effected by trace elements, like carbonates. If you live in London you have very hard water because of the presence of calcium carbonate, if you live in Glasgow you have very soft water because of the relative absence of these elements. Not only this but certain types of malted grain also radically effect the PH of the water which is itself directly effected by trace elements. So to reiterate, you have temperature, the types of malted grain and the relative alkalinity of the water which is dependent on trace elements all interplaying to effect the enzymatic process of conversion and its efficiency.

Now here is the crux of the matter. This enzymatic process requires calcium to be present. Calcium sulphate or calcium chloride. The problem with adding these to the water is that they reduce the PH. So if on top of that you have certain types of malted grain like dark malts these also reduce the PH taking it beyond accepted parameters. Therefore to combat this we add calcium carbonate which raises the PH to acceptable levels.

It was this relationship between calcium carbonate and calcium sulphate/chloride that I never understood with regard to how they effect the PH of water in relation to the enzymatic process of converting starches in malted grains to fermentable and not so fermentable sugars. Now I think I understand it.

R
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Originally posted by googlefudge
LMGTFY

Bicarbonate formula HCO3-
Carbonate formula CO3--
Gypsum CaSO4·2H2O
Chalk [main component] CaCO3

https://en.wikipedia.org/wiki/Bicarbonate
https://en.wikipedia.org/wiki/Carbonate
https://en.wikipedia.org/wiki/Chalk
https://en.wikipedia.org/wiki/Gypsum
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.

rc

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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.
Thankyou Mr Shmo.

rc

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Ok the upshot of this is that in order for me to get a balanced water profile based on the
data from my water company I will need to treat my water as follows.

Water supply zone Carron Valley B

Calcium mgCa/l - 9.89
Magnesium mgMg/l - 1.10
Hardness mg/l as CaCo3 - 29.19 (HCO3- 35.61)

Sulphate mgSO4/l - 13.91
Sodium mgNa/l - 4.63
Chloride mgCl/l - 8.14

Volume 32 litres

Chalk CaCO3 - 2g add 0.53 tsp
Baking Soda NaHCO3 - 1g add 0.23 tsp
Gypsum CaSO4 - 2g add 0.50 tsp
Calcium Chloride CaCl2 - 3.2g add 0.94 tsp
Epsom Salt MgSO4 - 1g add 0.22 tsp

😀

twhitehead

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You should be able to get testing equipment to test the pH of your final solution. Fish shops (for aquariums) should have kits as aquariums need to be a particular pH.

s
Fast and Curious

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Originally posted by twhitehead
You should be able to get testing equipment to test the pH of your final solution. Fish shops (for aquariums) should have kits as aquariums need to be a particular pH.
Also swimming pool places have Ph sticks, you immerse them in the solution and read out the color to get the Ph.

If you want to spend some bucks, you can get a Ph meter which gives you a fairly accurate digital readout.

LMGTHAT4U🙂

http://www.amazon.com/b?node=393271011

These guys are $20. Pretty cheap and accurate so the labels say.

rc

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Originally posted by twhitehead
You should be able to get testing equipment to test the pH of your final solution. Fish shops (for aquariums) should have kits as aquariums need to be a particular pH.
Actually by then its too late, PH is only really relevant to the process during the conversion process. We test the specific gravity of the final solution as we can use this to calculate the potential for converting sugars to alcohol expressed as ABV, alcohol by volume. Typical British beer is around 4-6 percent, whereas American beers can go from around 5 right up to 11-12 percent. The Brits have the best malts and the best yeast strains and the Americans have the best hops. The trend at present is to mix the two to get the best of both worlds.

rc

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Originally posted by sonhouse
Also swimming pool places have Ph sticks, you immerse them in the solution and read out the color to get the Ph.

If you want to spend some bucks, you can get a Ph meter which gives you a fairly accurate digital readout.

LMGTHAT4U🙂

http://www.amazon.com/b?node=393271011

These guys are $20. Pretty cheap and accurate so the labels say.
One can spend between twenty bucks and six hundred bucks for a PH meter. The cheaper ones need to be calibrated and the probes are expendable. Their accuracy remains a matter of some controversy. I think they should be ok but I prefer specialist litmus paper with a range of 4-6 PH, Normally PH paper comes within a range of 1-14, but the brewer needs more accuracy than they can provide so a narrow range is better.

s
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Originally posted by robbie carrobie
One can spend between twenty bucks and six hundred bucks for a PH meter. The cheaper ones need to be calibrated and the probes are expendable. Their accuracy remains a matter of some controversy. I think they should be ok but I prefer specialist litmus paper with a range of 4-6 PH, Normally PH paper comes within a range of 1-14, but the brewer needs more accuracy than they can provide so a narrow range is better.
Litmus paper, SO 20th century🙂 I know we had problems calibrating our Ph meters at work and I know for a fact they were not the 20 dollar variety! They come with several bottles of various Ph readings so you calibrate them accordingly. The good ones have a semipermeable glass coating on the actual probe material so it limits damage to the metals of the probe, and you can clean them with a neutral Ph solution but it takes a while.

rc

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Originally posted by sonhouse
Litmus paper, SO 20th century🙂 I know we had problems calibrating our Ph meters at work and I know for a fact they were not the 20 dollar variety! They come with several bottles of various Ph readings so you calibrate them accordingly. The good ones have a semipermeable glass coating on the actual probe material so it limits damage to the metals of the probe, and you can clean them with a neutral Ph solution but it takes a while.
yes even the twenty dollar ones come with two calibrating solutions which you are supposed to mix with distilled water. Some of the twenty dollar ones even have automatic temperature adjusting! (reading PH is temperature dependent I think) I think the idea is that you keep the probes moist when not in use, I cannot say why though. Cleaning them with distilled water makes sense.

s
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Originally posted by robbie carrobie
yes even the twenty dollar ones come with two calibrating solutions which you are supposed to mix with distilled water. Some of the twenty dollar ones even have automatic temperature adjusting! (reading PH is temperature dependent I think) I think the idea is that you keep the probes moist when not in use, I cannot say why though. Cleaning them with distilled water makes sense.
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.

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