Class 12 Chemistry - Chapter The Solid State NCERT Solutions | Refractive index of a solid is observed
Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property?
The solids are classified into two types:
a) Crystalline /true solids
b) Amorphous solids
To distinguish between crystalline and amorphous solids, isotropy and anisotropy plays a vital role.
Isotropy – The substances which have the same physical properties such as electrical conductivity, thermal conductivity, mechanical strength, refractive index etc. in all the directions in the space are called isotropic substances and this property is called as isotropy.
Anisotropy – The substances which have physical properties such as electrical conductivity, thermal conductivity, mechanical strength, refractive index etc. different in different directions in the space are called anisotropic substances and the property is called as anisotropy.
So a isotropic solid will have same refractive index in all the directions. Hence, amorphous solids are isotropic in nature. The reason for this is that in amorphous solids the arrangement of particles is random and disordered, therefore all directions are equivalent and properties are independent of direction .On the other hand, the particles in a crystalline solids are arranged & well ordered. Thus the arrangement of particles may be different in different directions.
CLEAVAGE-A crystalline solid when cut with a sharp edged tool such as knife gives a clean cleavage but an amorphous solid undergoes an irregular cleavage i.e. when an amorphous solid is cut with a sharp edged tool, it cuts into two pieces with irregular surfaces.
More Questions From Class 12 Chemistry - Chapter The Solid State
- Q:-
If NaCl is doped with 10-3mol % of SrCl2, what is the concentration of cation vacancies?
- Q:-
A cubic solid is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body-centre. What is the formula of the compound? What are the coordination numbers of P and Q?
- Q:-
An element with molar mass 2.7 x 10-2kg mol-1 forms a cubic unit cell with edge length 405 pm. If its density is 2.7 x 103 kg m-3, what is the nature of the cubic unit cell?
- Q:-
Copper crystallises into a fcc lattice with edge length 3.61 x 10-8cm. Show that the calculated density is in agreement with its measured value of 8.92 g cm-3.
- Q:-
A compound is formed by two elements M and N. The element N forms ccp and atoms of M occupy 1/3rd of tetrahedral voids. What is the formula of the compound?
- Q:-
Aluminium crystallises in a cubic close-packed structure. Its metallic radius is 125 pm.
(i) What is the length of the side of the unit cell?
(ii) How many unit cells are there in 1.00 cm3of aluminium?
- Q:-
Analysis shows that nickel oxide has the formula Ni0.98 O1.00. What fractions of nickel exist as Ni2+and Ni3+ions?
- Q:-
Distinguish between
(i)Hexagonal and monoclinic unit cells
(ii) Face-centred and end-centred unit cells.
- Q:-
Solid A is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?
- Q:-
Ionic solids, which have anionic vacancies due to metal excess defect, develop colour. Explain with the help of a suitable example.
Popular Questions of Class 12 Chemistry
- Q:-
For the reaction R → P, the concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds.
- Q:-
Write the formulas for the following coordination compounds:
(i) Tetraamminediaquacobalt (III) chloride
(ii) Potassium tetracyanonickelate(II)
(iii) Tris(ethane-1,2-diamine) chromium(III) chloride
(iv) Amminebromidochloridonitrito-N-platinate(II)
(v) Dichloridobis(ethane-1,2-diamine)platinum(IV) nitrate
(vi) Iron(III) hexacyanoferrate(II)
- Q:-
(i) Write structures of different isomeric amines corresponding to the molecular formula, C4H11N
(ii) Write IUPAC names of all the isomers.
(iii) What type of isomerism is exhibited by different pairs of amines?
- Q:-
Write any two characteristics of Chemisorption.
- Q:-
Write the structures of the following compounds.
(i) α-Methoxypropionaldehyde
(ii) 3-Hydroxybutanal
(iii) 2-Hydroxycyclopentane carbaldehyde
(iv) 4-Oxopentanal
(v) Di-sec-butyl ketone
(vi) 4-Fluoroacetophenone
- Q:-
Which of the ores mentioned in Table 6.1 can be concentrated by magnetic separation method?
- Q:-
Why are pentahalides more covalent than trihalides?
- Q:-
Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element?
- Q:-
Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.
- Q:-
Write structures of the following compounds:
(i) 2-Chloro-3-methylpentane
(ii) 1-Chloro-4-ethylcyclohexane
(iii) 4-tert. Butyl-3-iodoheptane
(iv) 1,4-Dibromobut-2-ene
(v) 1-Bromo-4-sec. butyl-2-methylbenzene
Recently Viewed Questions of Class 12 Chemistry
- Q:-
What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of their atoms :
3d3, 3d5, 3d8 and 3d4?
- Q:-
What happens when D-glucose is treated with the following reagents? (i)HI (ii)Bromine water (iii)HNO3
- Q:-
Write IUPAC names of the following compounds:
- Q:-
What is meant by 'disproportionation'? Give two examples of disproportionation reaction in aqueous solution.
- Q:-
What are the common types of secondary structure of proteins?
- Q:-
Give the uses of freon 12, DDT, carbon tetrachloride and iodoform.
- Q:-
How is leaching carried out in case of low grade copper ores?
- Q:-
Explain why Cu+ ion is not stable in aqueous solutions?
- Q:-
Explain why propanol has higher boiling point than that of the hydrocarbon, butane?
- Q:-
Is it true that under certain conditions, Mg can reduce SiO2 and Si can reduce MgO? What are those conditions?
- All Chapters Of Class 12 Chemistry
- All Subjects Of Class 12