Advertisements
Advertisements
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.
Advertisements
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:
\[\ce{\underset{(A)}{KMnO4} ->[Δ] \underset{(B)}{K2MnO4} + \underset{(C)}{MnO2} + O2}\]
\[\ce{MnO2 + KOH + O2 -> 2K2MnO4 + 2H2O}\]
\[\ce{MnO2 + 4NaCl + 4H2SO4 -> \underset{(D)}{MnCl2} + 2NaHSO4 + 2H2O + Cl2}\]
APPEARS IN
संबंधित प्रश्न
ln which pair highest oxidation states of transition metals are found:
Account for the following:
Cu+ ion is unstable in aqueous solution.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iodide.
Compare the stability of +2 oxidation state for the elements of the first transition series.
How would you account for the following:
Of the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.
What is meant by ‘disproportionation’?
Use Hund’s rule to derive the electronic configuration of Ce3+ ion and calculate its magnetic moment on the basis of ‘spin-only’ formula.
Explain why Mn2+ is more stable than Fe2+ towards oxidation to +3 state. (At. no. of Mn = 25, Fe = 26)
Give reason for the following:
The transition metals generally form coloured compounds.
Electronic configuration of Mn2+ is ____________.
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
Why does copper not replace hydrogen from acids?
Transition elements show high melting points. Why?
Match the properties given in Column I with the metals given in Column II.
| Column I (Property) | Column II (Metal) | |
| (i) | An element which can show +8 oxidation state | (a) \[\ce{Mn}\] |
| (ii) | 3d block element that can show | (b) \[\ce{Cr}\] |
| upto +7 oxidation state | (c) \[\ce{Os}\] | |
| (iii) | 3d block element with highest melting point | (d) \[\ce{Fe}\] |
Match the solutions given in Column I and the colours given in Column II.
| Column I (Aqueous solution of salt) |
Column II (Colour) |
| (i) \[\ce{FeSO2.7H2O}\] | (a) Green |
| (ii) \[\ce{NiCl2.4H2O}\] | (b) Light pink |
| (iii) \[\ce{MnCl2.4H2O}\] | (c) Blue |
| (iv) \[\ce{CoC12,6H2O}\] | (d) Pale green |
| (v) \[\ce{Cu2 Cl2}\] | (e) Pink |
| (f) Colourless |
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?
On adding NaOH, solution to the aqueous solution of K2CrO7 the colour of the solution changes from
Why Zn, Cd and Hg are not called transition metals?
The disproportionation of \[\ce{MnO^{2-}_4}\] in acidic medium resulted in the formation of two manganese compounds A and B. If the oxidation state of Mn in B is smaller than that of A, then the spin-only magnetic moment (µ) value of B in BM is ______. (Nearest integer)
Which property of transition metals enables them to behave as catalysts?
