Jome
Hazard to Others
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 154
Registered: 10-6-2004
Location: Soutwest sweden
Member Is Offline
Mood: desiccated
|
|
Acid decomposition of hypochlorite
Reaction w. an acid and hypochlorite yields chlorine, but how does the reaction go?
Something like this?:
H2SO4+NaClO(aq)--->NaHSO4(aq)+HClO(aq), 4HClO is dehydrated by H2SO4 into 2 mol of Cl2 and 1 mol of O2.
w. HCl(aq) one would get something like:
HCl(aq...)+NaClO--->NaCl+HClO HClO+HCl-->H2O+Cl2?
Is this correct?
|
|
neutrino
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline
Mood: oscillating
|
|
Your second equation is correct. The net ionic equation here is:
Cl- + ClO- + 2H+ ---> H<sub>2</sub>O + Cl<sub>2</sub>
Note that a source of chloride ions is unnecessary when using bleach or pool chlorinator, because these already have a stoichiometric amount.
|
|
woelen
Super Administrator
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 7998
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
The last remark is not always true. I have calcium hypochlorite, Ca(ClO)2.2H2O. This compound has no chloride (well, it has, but only as impurity).
If you add some dilute HNO3 to this, then you do get some Cl2, but the reaction is much slower than when dilute HCl is added.
|
|
chloric1
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1095
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Online
Mood: Stoichiometrically Balanced
|
|
Ca(OH)2 addition
From the processes I have read about, the Ca(OH)2 is chlorinated to the hypochlorite and addtional Ca(OH)2 is added to precipitate with the chloride
the insoluble double salt CaCL2*Ca(OH)2. This also help to stabilize the hypochlorite. This is important because even a small amount of oxidizable
contaminent introduced into a large mass of the hypochlorite could cause an autocatalytic decomposition of the ENTIRE mass of product possibly
rupturing the container or much worse. I believe once a small portion reached 180C from external heating or by chemical reaction the autocatalytic
throughout the mass commences. ![:o](./images/smilies/shocked.gif)
Fellow molecular manipulator
|
|
neutrino
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline
Mood: oscillating
|
|
I didn't know about that purification step. Now that I do the math, 70% calcium hypochlorite would have a lack of chloride if left untreated. Thanks
for pointing this out.
|
|