|
Posted by David C. Stone on March 11, 2005, 2:13 pm
Please log in for more thread options
> >
> > And decidedly inorganic. Lime is technically calcium oxide, however,
> > not calcium carbonate. Slaked lime is calcium hydroxide. While this
> > might seem pedantic, it makes a BIG difference if you're trying to
> > make mortar, cement, or concrete!!
> >
>
>
> technically your are right even though you are wrong ;o) actually, lime can
> be calcium carbonate. Look at this website
>
> http://hubcap.clemson.edu/~blpprt/acid4.html
>
>
> here is a quote from it:
>
> Lime. A material which, upon reaction with the soil, increases pH (decreases
> soil acidity) and does not add harmful elements to the soil. Usually, lime
> consists of finely ground carbonates of calcium and magnesium, although the
> term also includes oxides and hydroxides of calcium.
I was just going by my usual source, The Oxford Dictionary of Chemistry.
Ebbing's "General Chemistry" says the same thing, and mentions that
lime is also sometimes referred to as quicklime. Interestingly enough,
there's a photo in that book which shows a barge spraying limestone
slurry into a lake in order to raise the pH.
The site you reference is an agricultural one, and it doesn't suprise
me that "agricultural lime" is a mixture of stuff. I don't think I'd
want to put pure calcium oxide on my flower beds for the same reason
I wouldn't want to put it in a fish tank. Chemically and geologically
speaking, however, lime is calcium oxide. It's all down to context!!
|
|
Posted by Elaine T on March 11, 2005, 8:09 pm
Please log in for more thread options
Squeek wrote:
> If you add sodium bicarbonate for hardness, the buffering capacity wont last
> as long as adding organic lime to buffer....
That doesn't agree with anything I learned in chemistry class.
Carbonate is carbonate, and calcium has NO effect on pH.
--
__ Elaine T __
><__'> http://eethomp.com/fish.html <'__><
|
|
Posted by Mean_Chlorine on March 12, 2005, 4:25 am
Please log in for more thread options
>> If you add sodium bicarbonate for hardness, the buffering capacity wont last
>> as long as adding organic lime to buffer....
>
>That doesn't agree with anything I learned in chemistry class.
>Carbonate is carbonate, and calcium has NO effect on pH.
No, no, he's right - while it is true that the calcium doesn't really
matter, limestone dissolves slowly and is usually of much greater mass
than the bicarbonate you add to an aquarium, and so provides more
buffering under a much longer time. Also, the rate of dissolution of
limestone is directly proportional to pH, and so to the acids produced
in the aquarium.
|
|
Posted by Elaine T on March 12, 2005, 4:45 am
Please log in for more thread options
Mean_Chlorine wrote:
>
>
>>>If you add sodium bicarbonate for hardness, the buffering capacity wont last
>>>as long as adding organic lime to buffer....
>>
>>That doesn't agree with anything I learned in chemistry class.
>>Carbonate is carbonate, and calcium has NO effect on pH.
>
>
> No, no, he's right - while it is true that the calcium doesn't really
> matter, limestone dissolves slowly and is usually of much greater mass
> than the bicarbonate you add to an aquarium, and so provides more
> buffering under a much longer time. Also, the rate of dissolution of
> limestone is directly proportional to pH, and so to the acids produced
> in the aquarium.
>
Ah. I was assuming molar equivalents. A hunk of coral definately
buffers more than a teaspoon of baking soda. It sure makes the water
hard, though.
--
__ Elaine T __
><__'> http://eethomp.com/fish.html <'__><
|
| Similar Threads | Posted | | cloudy water | April 1, 2007, 5:04 am |
| Does old water conditioner go bad? | April 10, 2007, 12:09 pm |
| Re: Water heater | April 11, 2006, 12:31 pm |
| Re: Water Department | April 24, 2006, 1:39 pm |
| Re: Water Department | April 24, 2006, 1:41 pm |
| Re: Water Department | April 24, 2006, 3:14 pm |
| Water Department | April 24, 2006, 1:02 pm |
| Cloudy Water | October 13, 2008, 2:21 pm |
| foggy water | February 8, 2009, 3:37 pm |
| Don't Forget to do your water changes. | May 24, 2009, 8:14 am |
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap
> > And decidedly inorganic. Lime is technically calcium oxide, however,
> > not calcium carbonate. Slaked lime is calcium hydroxide. While this
> > might seem pedantic, it makes a BIG difference if you're trying to
> > make mortar, cement, or concrete!!
> >