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प्रश्न
Why \[\ce{HCl}\] should not be used for potassium permanganate titrations?
Why is permanganate titration not carried out in the presence of \[\ce{HCl}\]?
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उत्तर
Permanganate titrations in the presence of hydrochloric acid are unsatisfactory since hydrochloric acid is oxidised to chlorine. Permanganate titration cannot be performed with hydrochloric acid as it can be oxidized to produce chlorine gas. As a result, we do not obtain accurate endpoints for any titration.
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संबंधित प्रश्न
When chromite ore FeCr2O4 is fused with NaOH in presence of air, a yellow-coloured compound (A) is obtained, which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms an orange coloured crystalline compound (C).
(i) Write the formulae of the compounds (A), (B) and C.
(ii) Write one use of compound (C).
Complete the following equations : MnO4- + 4H+ + 3e- →
Name the oxometal anions of the first series of the transition metals in which the metal exhibits the oxidation state equal to its group number.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with iron (II) ions? Write the ionic equation for the reaction.
Give an example and suggest a reason for the following feature of the transition metal chemistry:
The highest oxidation state is exhibited in oxoanions of a metal.
Write the formula of an oxo-anion of Manganese (Mn) in which it shows the oxidation state equal to its group number.
Complete the following equations:
`2MnO_4^(-)+16H^++5S^(2-)rarr`
In the form of dichromate, \[\ce{Cr (VI)}\] is a strong oxidising agent in acidic medium but \[\ce{Mo (VI)}\] in \[\ce{MoO3}\] \[\ce{and W (VI)}\] in \[\ce{WO3}\] are not because:
(i) \[\ce{Cr(VI)}\] is more stable than \[\ce{Mo(VI)}\] and \[\ce{and W(VI)}\].
(ii) \[\ce{Mo(VI)}\] and \[\ce{and W(VI)}\] are more stable than \[\ce{Cr(VI)}\].
(iii) Higher oxidation states of heavier members of group-6 of transition series are more stable.
(iv) Lower oxidation states of heavier members of group-6 of transition series are more stable.
Potassium permanganate on heating at 513 K gives a product which is ______.
Indicate the steps in the preparation of \[\ce{K2Cr2O7}\] from chromite ore.
