Short Answer TypeAssign reasons for the following:
(i) Copper (I) ion is not known in aqueous solution.
(ii) Actinoids exhibit greater range of oxidation states than Lanthanoids.
Silver crystallizes in face-center cubic unit cell. Each side of this unit cell has a length of 400 pm. Calculate the radius of the silver atom. (Assume the atoms just touch each other on the diagonal across the face of the unit cell. That is each face atom is touching the four corner atoms.)
Nitrogen pentoxide decomposes according to equation: 2N2O5(g)---> 4NO2(g) + O2(g)
This first order reaction was allowed to proceed at 40° C and the data below were collected:
|
[N2O5] (M) |
Time (min) |
|
0.400 |
0.00 |
|
0.289 |
20.0 |
|
0.209 |
40.0 |
|
0.151 |
60.0 |
|
0.109 |
80.0 |
(a) Calculate the rate constant. Include units with your answer.
(b) What will be the concentration of N2O5 after 100 minutes?
(c) Calculate the initial rate of reaction.
Explain how the phenomenon of adsorption finds application in each of the following processes:
(i) Production of vacuum
(ii) Heterogeneous catalysis
(iii)Froth Floatation process
i) Production of high vacuum: Traces of air can be adsorbed by charcoal from a vessel, evacuated by a vacuum pump to give a very high vacuum.
(ii) Heterogeneous catalysis: heterogeneous catalysis refers to the form of catalysis where the phase of the catalyst differs from that of the reactants. Phase here refers not only to solid, liquid, or gas, but also immiscible liquids, e.g. oil and water
For example: N2(g) + 3H2(g) 
2NH3(g)
(iii) Froth floatation process: This process is used to remove gangue from sulphide ores. The basic principle involved in this process is adsorption. In this process, a mixture of water and pine oil is taken in the tank. The impure powdered sulphide ore is dropped in through hopper and the compressed air is blown in through the agitator. The agitator is rotated several times. As a result, the froth is formed and the sulphide ores get adsorbed in the froth. The impurities settled down and are let out through an outlet at the bottom. The froth formed is collected in froth collector tank. After sometime, the ore particles in the froth collecting tank start settling gradually, which are then used for further metallurgical operations.
Describe the principle behind each of the following processes:
(i)Vapour phase refining of a metal.
(ii)Electrolytic refining of a metal.
(iii)Recovery of silver after silver ore was leached with NaCN.
Write the name, stereochemistry and magnetic behavior of the following:
(At. nos. Mn = 25, Co = 27, Ni = 28)
(i) K4[Mn (CN)6]
(ii) [Co (NH3)5Cl]Cl2
(iii) K2[Ni (CN)4]
Switch
