CBSE chemistry
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How many atoms constitute one unit cell of a face-centered cubic crystal?
Number of atoms in one face centred cubic unit cell can be determined:-
(i) 8 corners atoms × 1/8 per corner atom = 
= 1 atom
(ii) 6 face-centered atoms × 1/ 2 atom per unit cell = 
= 3 atoms
∴ Total number of atoms per unit cell = 4 atoms
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Name the method used for the refining of Nickel metal?
Nickel is refined by mond’s process .In this process, nickel is heated in the presence of carbon monoxide to form nickel tetracarbonyl, which is a volatile complex.
Then, the obtained nickel tetracarbonyl is decomposed by subjecting it to a higher temperature (450-470) to obtain nickel metal.
What is the covalency of nitrogen in N2O5?
In N2O5, the covalency of N is restricted to 4 due to sp2 hybridization of nitrogen atom involving one 2s and three 2p orbitals.
Arrange the following in increasing order of their basic strength in aqueous solution:
CH3NH2, (CH3)3N, (CH3)2NH
With the increase in the alkyl group, the +I effect will increase which will increase the ease of donation of lone pair electron. But in water one other factor is controlling the strength of basicity.
Amine will accept a proton and from cation will be stabilised in water by salvation (by hydrogen bonding) better the salvation by hydrogen bonding higher will be the basic strength.
(CH3)3N<CH3NH2< (CH3)2NH
18 g of glucose, C6H12O6 (Molar Mass = 180 g mol-1) is dissolved in 1 kg of water in a saucepan. At what temperature will this solution boil?
(Kb for water = 0.52 K kg mol-1, boiling point of pure water = 373.15 K)
w1 = weight of solvent (H2O) = 1 kg
w2 = weight of solute (C6H12O6) = 18 gm
M2 = Molar mass of solute (C6 H12O6) = 180 g mol-1
Kb = 0.52 K Kg mol-1
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Mock Test Series
Mock Test Series