The lattice site in a pure crystal cannot be occupied by __________.
(A) Molecule
(B) Ion
(C) Electron
(D) Atom
(A) Molecule
(B) Ion
(C) Electron
(D) Atom
(C) Electron
The total number of tetrahedral voids in the face centred unit cell is _____.
(A) 6
(B) 8
(C) 10
(D) 12
What is the coordination number in a square close packed structure in two dimensions?
(A) 2
(B) 3
(C) 4
(D) 6
Graphite cannot be classified as __________.
(A) Conducting solid
(B) Network solid
(C) Covalent solid
(D) Ionic solid
Which of the following is an amorphous solid?
(A) Graphite (G)
(B) Quartz glass (SiO2)
(C) Chrome alum
(D) Silicon carbide (SiC)
Which stoichiometric defect does not change the density of the crystal?
(A) Frenkel defect
(B) Schottky defect
(C) Interstitial defect
(D) F-centres
Aryl halides can not be prepared by the reaction of arylalcohols with \(PCl_3\), \(PCl_5\) or \(SOCl_2\) because :
(a) phenols are highly stable compounds.
(b) carbon-oxygen bond in phenols has a partial doublebond character.
(c) carbon-oxygen bond is highly polar
(d) all of these
A Grignard reagent may be made by reacting magnesium with
a) Methyl amine.
b) Diethyl ether.
c) Ethyl iodide.
d) Ethyl alcohol.
The reaction R-Br + NaCN → R – CN + NaBr is an example of –
(a) Elimination Reaction.
(b) Nucleophilic Substitution.
(c) Electrophilic Substitution.
(d) Oxidation Reduction.
Why is Helium used in divers' tank but not hydrogen gas?
a) Helium is lighter than hydrogen.
b) Helium is inert to any chemical reactions.
c) Helium is cheaper.
d) Helium is easy to get from market.
\(SO_2\) is ----------and \(TeO_2\) is -------- agent
a) reducing, an oxidising
b) an oxidising, reducing
c) reducing, reducing
d) an oxidising, an oxidising
Assertion: Glycine must be taken through diet.
Reason: It is essential amino acid.
A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.
Which of the following alcohols will give the most stable carbocation during dehydration?
(a) 2-methyl-1-propanol.
(b) 2-methyl-2-propanol.
(c) 1-Butanol.
(d) 2-Butanol.