Ionic Form of KI + H2O Reaction

In summary: One of the students came across this video on YouTube and it really opened their eyes. Unfortunately, a lot of schools still teach the outdated theory that O2 is always present in redox reactions and that the presence of water somehow negates the ability of the I- to react. I think this is a really important topic to discuss as it definitely has an impact on the way we think about and approach chemistry problems. -In summary, Daniel says that the starch test will not work without molecular iodide however, I2. The reaction is K + I + H2O --> KOH + I + H. He thinks something is a miss here.
  • #1
airheadan
6
0
We need to know what the products of KI + H2O in ionic form.
 
Chemistry news on Phys.org
  • #2
The reaction should be

[tex] 2KI+H_{2}O\rightleftharpoons K_{2}O+2HI [/tex]

which in ionic form

[tex] 2K^{+}+2I^{-}+H^{+}+OH^{-}\rightleftharpoons 2K^{+}+O^{2-}+2H^{+}+2I^{-} [/tex]

I don't see any redox here...

Daniel.
 
  • #3
THe labis on oxidation reduction. It says that ppt turns pink in the presence of hyrdroxide ions and the starch will turn black/blue in the presence of molecular iodine. We figured that this meant that in the equation that this meant in the products their will be a hydroxide ions and an I molecule. We thought that the answer you gave us was right but our teacher said that we were closer when we showed him KI + H2O--> OH + K + I2 + H
 
  • #4
Yes,i didn't think of that option.There it is.Can u find the coefficients by accomplishing the electron transfer ?

[tex] aK^{+}+bI^{-}+cH^{+}+dOH^{-}\rightleftharpoons eK^{+}+fOH^{-}+gI_{2}+h H_{2}\uparrow [/tex]

Daniel.
 
  • #5
yeah we should be able to, um what are the a,b,c,d,e,f,g for?
 
  • #6
Coefficents,like 1,2,1/2,3/2,3.

So who's getting oxidated and who's getting reduced...?

Daniel.
 
  • #7
umm I haven't done it yet;P
 
  • #8
It's not funny.If u haven't done redox reactions in school,why do you bother with this problem...?:rolleyes:

Daniel.
 
  • #9
Me thinks something is a miss here. Was it hydroxide or peroxide ?
 
  • #10
it was hydroxide
 
  • #11
airheadan said:
THe labis on oxidation reduction. It says that ppt turns pink in the presence of hyrdroxide ions and the starch will turn black/blue in the presence of molecular iodine.

OK what is ppt ?
 
  • #13
the ppt is phenalthailene...and the reaction is K + I + H2O --> KOH + I + H
 
  • #14
teacher said that we were closer when we showed him KI + H2O--> OH + K + I2 + H

Alright, I would imagine that this is a simple dissociation reaction, [tex]KI_{(s)}+H_2O \rightarrow K^{+}_{(aq)}+I^{-}_{(aq)} [/tex]

The starch test will not work without molecular iodide however, I2. You'll need both I2 and I-, for the iodine complex involving I3-.
 
  • #15
airheadan said:
the ppt is phenalthailene...and the reaction is K + I + H2O --> KOH + I + H

OK I'm highly dyslexic, but did you mean phenolphthalein ? There still is something a miss here (like what would oxidize the I-).
 
  • #16
K + I + H2O --> KOH + I + H

potassium reacts with water? Never actually encountered this before, I though it would be a spectator ion. I've read about this and it seems that KI is dissolved in water to provide I-, subsequently I2 is added to form I3-, which can form complexes with starch conterparts to form a colored solution.

I'm somewhat sensitive about the way some high schools deal with redox reactions as at times they are completely misleading and inaccurate. I've had a post in my forum a couple of months ago regarding a high school chemistry competition of which one of the answers provided turned out to be completely inaccurate. I couple of students decided to seek help online for references and quotes.
 

Related to Ionic Form of KI + H2O Reaction

1. What is the chemical equation for the ionic form of KI + H2O reaction?

The chemical equation for the ionic form of KI + H2O reaction is KI + H2O → K+ + I- + H2O.

2. What is the significance of the ionic form of KI + H2O reaction?

The ionic form of KI + H2O reaction is significant because it demonstrates the dissociation of KI into its constituent ions, potassium (K+) and iodide (I-), in the presence of water. This is a common reaction in aqueous solutions and is important in many chemical processes.

3. Can you explain the role of water in the ionic form of KI + H2O reaction?

Water plays a crucial role in the ionic form of KI + H2O reaction as it acts as a solvent, allowing the ions to separate and interact with each other. Additionally, water molecules can also interact with the ions, stabilizing them and preventing them from recombining.

4. Is the ionic form of KI + H2O reaction exothermic or endothermic?

The ionic form of KI + H2O reaction is exothermic, meaning it releases heat energy. This is because the formation of ions from the dissociation of KI is a highly spontaneous process, resulting in the release of energy.

5. What are some real-life applications of the ionic form of KI + H2O reaction?

The ionic form of KI + H2O reaction has several real-life applications. One example is in the production of iodide-containing drugs, such as potassium iodide tablets used to treat thyroid disorders. It is also used in the synthesis of certain organic compounds and in the purification of water. In addition, this reaction is also important in understanding the behavior of electrolyte solutions in batteries and other electrochemical systems.

Similar threads

  • Chemistry
Replies
4
Views
1K
Replies
3
Views
1K
Replies
5
Views
1K
  • Chemistry
Replies
3
Views
3K
  • Chemistry
Replies
7
Views
8K
Replies
6
Views
2K
Replies
4
Views
2K
Replies
6
Views
2K
Replies
4
Views
2K
Back
Top