The one subject in NEET which is candidates who can easily attain good marks is Chemistry. That's the reason, often, one doesn’t pay notice and choose to compromise it. But if one wants to rank above others, the tip is to be thorough with NEET chemistry concepts. The understanding of reactions and definite basic understanding is what requires major attention in Chemistry but once done it only gets simpler from there. The main focus on the to-do list should be on getting a hang of the NCERT syllabus of NEET chemistry..
Q1. The ionic radii of Rb+ andI− are 1.46 â„« and 2.16 â„«.
The most probable type of structure exhibited by it is
Solution
Given,
∴It will have coordination number 6 and structure will be same as of NaCl.
face centre positions. If one atom of B is missing from one of the face centred points, the formula of
the compound is
Solution
Number of atoms (A) per unit cell =8×1/8=1
Number of atoms (A) per unit cell =8×1/8=1
Number of atoms (B) per unit cell =(6−1)×1/2=5/2
(One atom B is missing)
Q4. A crystal may have one or more planes and one or more axes of symmetry but it possesses
Solution
A crystal possesses only one centre of symmetry.
A crystal possesses only one centre of symmetry.
Q5.Doping of silicon (Si) with boron (B) leads to
Solution
Doping of silicon with boron leads to p−type semiconductor.
Doping of silicon with boron leads to p−type semiconductor.
Q6. The ratio of cations to anion in a octahedral close packing is :
Solution
r+/r− for octahedral void = 0.414;
r+/r− for octahedral void = 0.414;
r+/r− for cubic = 0.732−1
Q7.For an ionic crystal of the general formula A+B− and co-ordination number 6, the radius ration will
be :
Solution
The radius ratio for co-ordination and has 4, 6, and 8 lies in between the ranges [0.225−0.414], [0.414−0.732] and [0.732−1] respectively.
The radius ratio for co-ordination and has 4, 6, and 8 lies in between the ranges [0.225−0.414], [0.414−0.732] and [0.732−1] respectively.
Q8.The cubic unit cell of Al (molar mass 27 g mol−1)has an edge length of 405 pm. Its density is
2.7 g cm−3. The cubic unit cell is
Solution
For face centred cubic unit cell, number of atoms are 4.
Q9.The statement that, “The crystals of same substance can have different shapes depending upon the
number and size of faces but the angle between the corresponding faces remains constant” is known as:
Solution
This is the law of constancy of interfacial angles.
This is the law of constancy of interfacial angles.
Q10. Which of the following will show anisotropy?
Solution
Crystalline solids are anisotropic since, they exhibit different properties in all directions.
Crystalline solids are anisotropic since, they exhibit different properties in all directions.