Talk:Calcium hydroxide

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hazards

The impression you get from reading the hazards is that this stuff is dangerously toxic, it is not, however. I think this should be changed. 194.53.253.51 (talk) 08:15, 22 April 2009 (UTC)[reply]

Error Redirect

I wrote in Calcium Hydrate, and was redirected to Calcium Hydroxide. These are not the same thing. Calcium Hydrate is Ca·6H2O [or Ca(aq)] (i believe - I actually came to check the number of water molecules per calcium ion), while Calcium Hydroxide is Ca(OH)2. I would stop the redirect, but I don't know how. :( - Baribeau 01:38, 27 November 2006 (UTC)[reply]

Ca.6H2O exists only in solution. If you dissolve CaCl2 in water, you'll probably get Ca²⁺ . xH2O. But in solid form, the only thing that you can get is the hydroxide, probably with a lot of water in the crystal structure.

article division

There should be separate articles for slaked lime, lime water, milk of lime and common applications, and Calcium hydroxide, Magnesium hydroxide with Chemistry etc. Same goes for Calcium Oxide / lime (mineral). Comments please PeterGrecian 14:26, 19 Apr 2005 (UTC)

isn't slaked lime the same thing as Calcium hydroxide. If so, why does it need its own article? --Duk 17:55, 6 October 2005 (UTC)[reply]

I disagree with this proposal. Put your effort into fleshing out this article and cleaning it up, as the tag asks us to. In the unlikely event that this one gets unwieldy, something could later be split out. Gene Nygaard 18:52, 6 October 2005 (UTC)[reply]

clean up.

I agree with your comments. Also... the formatting of the article is poor with lines chopped in two. Perhaps it has been copied from somewhere - and there are copywrite issues? Also what on earth is polikar! It looks like something Russian? CustardJack 16:55, 11 May 2005 (UTC)[reply]

further cleanup

I have tried to cleanup the grammar and style problems, although a few clunky bits remain. In particular, I was unsure as to whether to change the word "drug" to "chemical" or "preservative" in the last line of the "Uses" section. Also, the line "Because of its strong basic properties, calcium hydroxide has many varied uses as:" is very cumbersome and should be edited further. I also believe the phrase "but unrelated to the citrus fruit (lime)" should be removed and a link to a lime disambiguafication page placed at the top of the article, but I'm running out of time for editing right now. -Paul Foster 9:08, 23 May 2005 (EST)

One question: As to the dangers through overdose section, can't the difficulty breathing and internal bleeding be explained by the hypotension? - Guest 4:09, 3 Feb 2007 (Pacific Time)

The article states: "When heated to 512 °C, the partial pressure of water in equilibrium with calcium hydroxide reaches 101 kPa and decomposes into calcium oxide and water." This sentence needs to be edited, but since I don't have access to the reference, I can't do it. As this sentence reads now, the partial pressure of water decomposes into calcium oxide and water, which is nonsensical. Partial pressures don't decompose. —Preceding unsigned comment added by 75.26.143.229 (talk) 23:29, 27 May 2010 (UTC)[reply]

Tweaked. Materialscientist (talk) 23:34, 27 May 2010 (UTC)[reply]

Production

Are their any methods of production that are cheap and don't produce CO2 Ozone 19:16, 28 February 2006 (UTC)[reply]

No!! . . . LinguisticDemographer 13:39, 17 March 2007 (UTC)[reply]

There are expensive methods, which does not produces CO₂ (but produces SO₂). Starting material there would be calcium sulfate. SO₂ is worse for environment than CO₂, and in such case it could not be filtered, because the cheapest material for removing SO₂ from waste gas stream is calcium hydroxide itself. -Yyy (talk) 07:55, 2 March 2008 (UTC)[reply]

Link

would it be possible to add an shortcut for Ca(OH)2?because not everybody looks for Calcium Oxide...

Merger with Portlandite

There might be some argument for merging Portlandite (which is the crystalline mineral) into this, but not vice versa. Its crystalline mineral nature is just one of many attributes of calcium hydroxide. . . . LinguisticDemographer 13:45, 17 March 2007 (UTC)[reply]

Celts and hair

Now, I've heard that the celts washed their hair with slaked lime, or Calcium hydroxide, and so made it stiff and, also, bleached it. However, I'm struggling to find out if you can actually do this with lime alone, or if there were other ingredients involved, or what?

The details, unfortuantely, are not particularly thick on the ground. Here's a couple of links with most of what I know -

http://www.celticcoins.com/pages/131106.html

' "Their hair is blond, and not only naturally so, but they also make it their practice by artificial means to increase the distinguishing colour which nature has given it. For they are always washing their hair in lime-water, and they pull it back from the forehead to the top of the head and back to the nape of the neck with the result that their appearance is like that of Satyrs and Pans, since the treatment of their hair makes it so heavy and coarse that it differs in no respect from the mane of horses" '

http://www.123freehost.co.uk/sites/adam7daviesessays/

' The Celts bleached and spiked their hair with lime – one ancient writer wrote that each spike of hair was so sharp that an apple could be impaled on one! '

- I'd be very interested in knowing more about this, if anyone has the time to research it more deeply than I have.

41.243.78.15 15:15, 16 May 2007 (UTC)[reply]

Decomposition

One paragraph says Ca(OH)2 decomposes at 512 C, and the chembox at right says 580 C. Which is it? 97.82.247.200 10:02, 11 August 2007 (UTC)[reply]

Vapor pressure

In the intro there is a footnote that claims that 512°C is the temperature at which H₂O vapor pressure reaches 101 kPa. What on earth is meant here? At 100°C the vapor pressure of water reaches 101 kPa and it boils. Maybe this is meant to refer to the partial pressure of H2O over Ca(OH)2? --Slashme (talk) 10:22, 21 January 2008 (UTC)[reply]

Yes, it must be the partial pressure of H2O in the equilibrium Ca(OH)2 -> CaO + H2O(g). --Itub (talk) 13:02, 21 January 2008 (UTC)[reply]

sea water

Is it possible to make by reaction with sea water, instead of pure water? If so, what additional substances would be made. 86.30.179.100 (talk) 18:17, 15 November 2009 (UTC)[reply]

Metal and slaked lime

What happens if metal comes into contact with slaked lime?199.33.32.40 (talk) 02:46, 11 August 2010 (UTC)[reply]

The result depends on the metal, but for most commonly encountered metals, nothing would happen rapidly. In contact with base (such as Ca(OH)2) and water, most metals corrode to the oxides.--Smokefoot (talk) 14:19, 18 September 2010 (UTC)[reply]

Lutefisk? Really?

I'd like to see a cite about lutefisk made with calcium hydroxide, as opposed to lye. I'm skeptical that calcium hydroxide would even work. Francis Lima (talk) 21:31, 19 September 2010 (UTC)[reply]