Advertisements
Advertisements
प्रश्न
Identify A to E and also explain the reactions involved.
Advertisements
उत्तर
A = \[\ce{Cu}\]
B = \[\ce{Cu(NO3)2}\]
C = \[\ce{[Cu(NH3)4]}\]
D = \[\ce{CO2}\]
E = \[\ce{CaCO3}\]
F = \[\ce{Cu2[Fe(CN)6]}\]
G = \[\ce{Ca (HCO3)2}\]
\[\ce{CuCO3 -> CuO + CO2}\]
\[\ce{CuO + CuS -> \underset{(A)}{Cu} + SO2}\]
\[\ce{Cu + 4HNO3 (Conc) -> Cu \underset{(B)}{(NO3)2} + 2NO + 2H2O}\]
\[\ce{\underset{(B)}{Cu^2+} + NH3 -> \underset{(C)}{[Cu(NH3)4]}}\]
\[\ce{Ca(OH)2 + \underset{(D)}{CO2} -> \underset{(E)}{CaCO3} + H2O}\]
\[\ce{CaCO3 + CO2 + H2O -> Ca(HCO3)2}\]
APPEARS IN
संबंधित प्रश्न
ln which pair highest oxidation states of transition metals are found:
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element shows only +3 oxidation state?
Why are Mn2+ compounds more stable than Fe2+ towards oxidation to their +3 state?
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:
Electronic configurations
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
Explain why transition elements form alloys.
In lake test for Al3+ ions, there is the formation of coloured ‘floating lake’. It is due to ______.
Read the passage given below and answer the following question:
The transition metals when exposed to oxygen at low and intermediate temperatures form thin, protective oxide films of up to some thousands of Angstroms in thickness. Transition metal oxides lie between the extremes of ionic and covalent binary compounds formed by elements from the left or right side of the periodic table. They range from metallic to semiconducting and deviate by both large and small degrees from stoichiometry. Since electron bonding levels are involved, the cations exist in various valence states and hence give rise to a large number of oxides. The crystal structures are often classified by considering a cubic or hexagonal close-packed lattice of one set of ions with the other set of ions filling the octahedral or tetrahedral interstices. The actual oxide structures, however, generally show departures from such regular arrays due in part to distortions caused by packing of ions of different size and to ligand field effects. These distortions depend not only on the number of d-electrons but also on the valence and the position of the transition metal in a period or group.
In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.
Assertion: Cations of transition elements occur in various valence states.
Reason: Large number of oxides of transition elements are possible.
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?
Match the catalysts given in Column I with the processes given in Column II.
| Column I (Catalyst) | Column II (Process) |
| (i) \[\ce{Ni}\] in the presence of hydrogen | (a) Zieglar Natta catalyst |
| (ii) \[\ce{Cu2C12}\] | (b) Contact process |
| (iii) \[\ce{V2O5}\] | (c) Vegetable oil to ghee |
| (iv) Finely divided iron | (d) Sandmeyer reaction |
| (v) \[\ce{TiCl4 + Al (CH3)3}\] | (e) Haber's Process |
| (f) Decomposition of KCIO3 |
Sodium this sulphate is used in photography because of its:-
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
Which one of the following characters tie of the transition metal is associated with higher catalytic activity?
Why Zn, Cd and Hg are not called transition metals?
Which one among the following metals of the 3d series has the lowest melting point?
Complete the following reaction and justify that it is a disproportionation reaction:
\[\ce{3MnO^{2-}4 + 4H^+ -> \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{} + 2H2O}\]
In order to protect iron from corrosion, which one will you prefer as a sacrificial electrode, Ni or Zn? Why? (Given standard electrode potentials of Ni, Fe and Zn are -0.25 V, -0.44 V and -0.76 V respectively.)
Write the ionic equation for reaction of KI with acidified KMnO4.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
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.
