For kinetic study of the reaction of iodide ion with $$\mathrm{H}_{2} \mathrm{O}_{2}$$ at room temperature :
(A) Always use freshly prepared starch solution.
(B) Always keep the concentration of sodium thiosulphate solution less than that of KI solution.
(C) Record the time immediately after the appearance of blue colour.
(D) Record the time immediately before the appearance of blue colour.
(E) Always keep the concentration of sodium thiosulphate solution more than that of KI solution.
Choose the correct answer from the options given below :
In neutral or alkaline solution, $$\mathrm{MnO}_{4}^{-}$$ oxidises thiosulphate to :
Given below are two statements.
Statement I: Iron (III) catalyst, acidified $$\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$$ and neutral $$\mathrm{KMnO}_{4}$$ have the ability to oxidise $$\mathrm{I}^{-}$$ to $$\mathrm{I}_{2}$$ independently.
Statement II: Manganate ion is paramagnetic in nature and involves $$\mathrm{p} \pi-\mathrm{p} \pi$$ bonding.
In the light of the above statements, choose the correct answer from the options given below.
Match List I with List II.
List I Pollutant |
List II Disease/sickness |
||
---|---|---|---|
(A) | Sulphate (>500 ppm) | (I) | Methemoglobinemia |
(B) | Nitrate (>50 ppm) | (II) | Brown mottling of teeth |
(C) | Lead (>50 ppb) | (III) | Laxative effect |
(D) | Fluoride (>2 ppm) | (IV) | Kidney damage |
Choose the correct answer from the options given below: