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Chemistry: Post your doubts here!

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How one know that which MnO-4 half equation use

MnO4– + 4H++ 3e– MnO2 + 2H2O +1.67
MnO4– + 8H++ 5e– Mn2+ + 4H2O +1.52
 
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How many stereoisomers does piperic acid have? I mean the answer is 4 but i actually drew 8 of them and they are all different in terms of spatial arrangement. I hope you understand the spatial crisis here. I would be grateful if somebody could explain it to me.
 

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It just simply does not react with bromine 'No reaction occurs'.
Here the question is basically focusing on where the the bromine will attach what will be the specified position which in this case are 2 & 6 as -OH is electron donating group.
why does br2 not react with the double bond?
 
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Q3)b)
i) Why does Br2 not react with the double bond?
ii)why does ethyol chloride not react with N in the ring ?
 

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Hey can some one help with the concept of tetrahedral and square planer complex? How to differentiate between the two?
Also this question, how do we know which equation from databooklet to use for Fe3 : 1) Fe3 + 3e- => Fe or 2) Fe3 + e- => Fe2
 

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Hey can some one help with the concept of tetrahedral and square planer complex? How to differentiate between the two?
Also this question, how do we know which equation from databooklet to use for Fe3 : 1) Fe3 + 3e- => Fe or 2) Fe3 + e- => Fe2
For your first question,
you will not have to be able to tell the difference between square planar and tetrahedral just based on the formula. However, if there is a name of a coordination complex with four ligands and cis- or trans- is specified, then you know that the complex must be square planar because all positions on a tetrahedral complex are equivalent. If neither cis- or trans- is specified, the compound may be either square planar or tetrahedral and you will not need to know the difference.

And also it mentions in the syllabus Tetrahedral OR square planar complex I think it is considered the same.
 
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Hydrogen Iodide dissociates into H2 and I2.
2HI (g) <-----> H2 (g) + I2 (g) (the reaction goes in both directions)
In an experiment, b mol of hydrogen iodide were put into a sealed vessel at pressure p. At equilibrium, x mol of the hydrogen iodide had dissociated. Which expression for Kp is correct?
A. x^2/(b-x)^2 B. x^2×p^2/(b-x)^2 C. x^2×p^2/4b(b-x) D. x^2/4(b-x)^2
The ice table method doesnt work here. The answer is D.
I am getting x^2/(b-2x)^2
 
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Hydrogen Iodide dissociates into H2 and I2.
2HI (g) <-----> H2 (g) + I2 (g) (the reaction goes in both directions)
In an experiment, b mol of hydrogen iodide were put into a sealed vessel at pressure p. At equilibrium, x mol of the hydrogen iodide had dissociated. Which expression for Kp is correct?
A. x^2/(b-x)^2 B. x^2×p^2/(b-x)^2 C. x^2×p^2/4b(b-x) D. x^2/4(b-x)^2
The ice table method doesnt work here. The answer is D.
I am getting x^2/(b-2x)^2
x moles of HI have dissociated which will give x/2 moles of H2 and x/2 moles of I2
When u will write the expression, the numerator will be ( x/2)² = x²/4 and the 4 will go in the denominator to form x²/4(b-x)²
 
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In flooded soils, like those used for rice cultivation, the oxygen content is low. In such soils, anaerobic bacteria cause the loss of nitrogen from the soil as shown in the following sequence.

In which step is the change in oxidation number (oxidation state) of nitrogen different to the changes in the other steps?

NO3–(aq)
A
NO2–(aq)
B
NO(g)
C
N2O(g) N2(g


Please help guys
 
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