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A violet compound of manganese (A) decomposes on heating to liberate oxygen and compounds (B) and (C) of manganese are formed. Compound (C) reacts with KOH in the presence of potassium nitr - Chemistry

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प्रश्न

A violet compound of manganese (A) decomposes on heating to liberate oxygen and compounds (B) and (C) of manganese are formed. Compound (C) reacts with KOH in the presence of potassium nitrate to give compound (B). On heating compound (C) with conc. \[\ce{H2SO4}\] and \[\ce{NaCl}\], chlorine gas is liberated and a compound (D) of manganese along with other products is formed. Identify compounds A to D and also explain the reactions involved.

दीर्घउत्तर
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उत्तर

The compounds A, B, C and D are given as under:

A = \[\ce{KMnO4}\]

B = \[\ce{K2MnO4}\]

C = \[\ce{MnO2}\]

D = \[\ce{MnCl2}\]

The reactions are explained as under:

\[\ce{\underset{(A)}{KMnO4} ->[Δ] \underset{(B)}{K2MnO4} + \underset{(C)}{MnO2} + O2}\]

\[\ce{MnO2 + KOH + O2 -> 2K2MnO4 + 2H2O}\]

\[\ce{MnO2 + 4NaCl + 4H2SO4 -> \underset{(D)}{MnCl2} + 2NaHSO4 + 2H2O + Cl2}\]

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  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 8: The d-and f-Block Elements - Multiple Choice Questions (Type - I) [पृष्ठ ११५]

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एनसीईआरटी एक्झांप्लर Chemistry [English] Class 12
पाठ 8 The d-and f-Block Elements
Multiple Choice Questions (Type - I) | Q 71 | पृष्ठ ११५

संबंधित प्रश्‍न

Why do interstitial compounds have higher melting points than corresponding pure metals?


Which metal in the first transition series (3d series) exhibits + 1 oxidation state most frequently and why?


Account for the following:

Cu+2 salts are coloured, while Zn2+ salts are white.


In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?


What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of its atom?

3d3


Predict which of the following will be coloured in the aqueous solution?

Ti3+, V3+, Cu+, Sc3+, Mn2+, Fe3+ and Co2+. Give reasons for each.


What is meant by ‘disproportionation’? 


Complete and balance the following chemical equations

`MnO_4^(-) + H_2O + I^(-) ->`


When \[\ce{KMnO4}\] solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because ______.


Transition elements show high melting points. Why?


When a chromite ore (A) is fused with sodium carbonate in free excess of air and the product is dissolved in water, a yellow solution of compound (B) is obtained. After treatment of this yellow solution with sulphuric acid, compound (C) can be crystallised from the solution. When compound (C) is treated with KCl, orange crystals of compound (D) crystallise out. Identify A to D and also explain the reactions.


Identify the metal and justify your answer.

Carbonyl \[\ce{M(CO)5}\]


The element with atomic number 46 belongs to


Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-


A complex in which dsp2 hybridisation takes place is ______.


The electrode potential of M2+/M of 3d-series elements shows the positive value for ______.


Which of the following characteristics of transition metals is associated with their catalytic activity?


Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)


Give a reason for the following:

Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.


For M2+/M and M3+/M2+systems, the EΘ values for some metals are as follows:

Cr2+/Cr −0.9 V
Mn2+/Mn −1.2 V
Fe2+/Fe −0.4 V
Cr3/Cr2+ −0.4 V
Mn3+/Mn2+ +1.5 V
Fe3+/Fe2+ +0.8 V

Use this data to comment upon:

The ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.


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