Advertisements
Advertisements
प्रश्न
What is meant by 'disproportionation'? Give two examples of disproportionation reaction in aqueous solution.
उत्तर
The oxidation and reduction of a substance at the same time as a result of a chemical reaction is called disproportionation. For example,
\[\ce{3\overset{0}{Cl2} + 6OH^- -> 5\overset{-1}{Cl}^- + \overset{+5}{Cl}O^-_3 + 3H2O}\]
\[\ce{3\overset{+6}{Mn}O^{2-}_4 + 4H^+ -> 2\overset{+7}{Mn}O^-_4 + \overset{+4}{Mn}O2 + 2H2O}\]
APPEARS IN
संबंधित प्रश्न
Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?
What are the characteristics of the transition elements and why are they called transition elements?
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iodide.
Write the formula of an oxo-anion of Chromium (Cr) in which it shows the oxidation state equal to its group number
Complete and balance the following chemical equations
`MnO_4^(-) + H_2O + I^(-) ->`
In lake test for Al3+ ions, there is the formation of coloured ‘floating lake’. It is due to ______.
Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of the following metallic ions have almost same spin only magnetic moment?
(i) \[\ce{Co^{2+}}\]
(ii) \[\ce{Cr^{2+}}\]
(iii) \[\ce{Mn^{2+}}\]
(iv) \[\ce{Cr^{3+}}\]
Although fluorine is more electronegative than oxygen, but the ability of oxygen to stabilise higher oxidation states exceeds that of fluorine. Why?
Explain why does colour of \[\ce{KMNO4}\] disappear when oxalic acid is added to its solution in acidic medium.
Assertion: Separation of \[\ce{Zr}\] and \[\ce{Hf}\] is difficult.
Reason: Because \[\ce{Zr}\] and \[\ce{Hf}\] lie in the same group of the periodic table.
Assertion: The highest oxidation state of osmium is +8.
Reason: Osmium is a 5d-block element.
Transition metals can act as catalysts because these can change their oxidation state. How does \[\ce{Fe(III)}\] catalyse the reaction between iodide and persulphate ions?
A metallic ion 'M' reacts with chloride ion to form white precipitate which is readily soluble in aqueous ammonia. Identify 'M'?
Photographic film and plates have - au essential ingredient of
Which of the following maxm magnetic moment?
Passing H2S gas into a mixture of Mn2+ and Ni2+, Cu2+, ions in an acidified aqueous solution precipitates.
Why is the `"E"_(("V"^(3+)//"V"^(2+)))^"o"` value for vanadium comparatively low?
Complete the following reaction and justify that it is a disproportionation reaction:
\[\ce{3MnO^{2-}4 + 4H^+ -> \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{} + 2H2O}\]
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Ionisation enthalpies
