CBSE Class 12 Chemistry Questions and basic easy to learn concepts/ notes Database for chapter Solid State. Based on CBSE and CCE guidelines. The students should practice these Questions to gain perfection which will help him to get more marks in CBSE examination. Based on CBSE and CCE guidelines. The preparation should be in a manner which helps the students to concentrate more in areas which carry more marks. Please refer to more CBSE Class XII sample papers, question papers, HOTs etc in other links.
As we know that matter exists in different physical states under different conditions of temperature and pressure. For example solid state, liquid gases plasma and BEC etc. Now we will study about different aspects of solid state.
1. The state of matter whose M.P is above room temp is solid state. Solids have definite shape and volume, having high density and constituent particles are held strongly.
2. Based on arrangement of particles types of solid : 1: Crystalline 2:Amorphous
3. Crystalline solids have regular arrangement of constituent particles throughout, melting point is sharp, Anisotropic in nature and give clear cut cleavage.
4. Amorphous solids have no regular arrangement, no sharp M.P, isotropic in nature they do not exhibit cleavage property.
5. Amorphous silica is used in photovoltaic cells.(Applications of amorphous solid)
6. Space lattice is the regular 3D, arrangement of constituent particles in the crystalline solid. It shows how the constituents particles(atoms, molecules etc.) are arranged.
7. Smallest repeating unit in a space lattice is called unit cell.
8. There are 4 types of unit cells, 7 crystal systems and 14 bravais lattices.
9. Types of unit cell No. of atoms per unit cell
i. Simple cubic unit cell 8*1/8=1
ii. FCC (Face centered cubic) 8*1/8+6*1/2=4
iii. BCC (Body centered cubic) 8*1/8+1*1=2
10. Hexagonal close packing and cubic close packing have equal efficiency i.e 74%
11. Packing efficiency =volume occupied by spheres (Particles)/volume of unit cell *100
12. For simple cubic unit cell the p.f.=1*4/3 *πr3/8*r3 *100 =52.4
13. The packing efficiency in fcc =4*4/3 *πr3/16*2 1/2 r3 *100 =74
14. The packing efficiency in bcc =2*4/3 *πr3/64*33/2 r3 *100 =68
15. The packing efficiency in hcp =74
16. Packing efficiency in bcc arrangement in 68% and simple cubic unit cell is 52.4%
17. Unoccupied spaces in solids are called interstitial voids or interstitial sites.
18. Two important interstitial voids are (I). Tetrahedral void and (II). Octahedral void.
19. Radius ratio is the ratio of radius of void to the radius of sphere. a. For tetrahedral void radius ratio=0.225 For octahedral void radius ratio=0.414
20. No. of tetrahedral void=2*N (N=No. of particles)
21. No. of octahedral void=N
22. Formula of a compound depends upon arrangement of constituent of particles. 23. Density of unit cell
D=density, M=Molar mass, a=side of unit cell, NA=6.022*1023
24. The relationship between edge length and radius of atom and interatomic or interionic distance for different types of unit is different as given below
Simple cubic unit cell a=2R
F C C a=4R/
B C C a=4R/
25. Interatomic distance=2R
26. Interionic distance=Rc+Ra (Rc=Radius of cation, Ra=Radius of anion)
27.Imperfection is the ir-regularty in the arrangement of constituent particles.
28.Point defect or Atomic defect-> it is the deviation from ideal arrangement of constituent atom. Point defects are two types (a) Vacancy defect (b) Interstitial defect
29.Vacancy defect lowers the density and
Please refer to the attached file for CBSE Class 12 Chemistry - Solid State Notes and Questions