Download 19. Define the term solution.. How many types of solutions

KENDRIYA VIDYALAYA CLRI
Class 12 Chemistry
Holiday Home work
2015-16
1.Why are solids rigid?
2.Why do solids have a definite volume?
3.Classify the following as amorphous or crystalline solids: Polyurethane, naphthalene,
benzoic acid, teflon, potassium nitrate, cellophane, polyvinyl chloride, fibre glass,
copper.
4.Classify the following solids in different categories based on the nature of
intermolecular forces operating in them:Potassium sulphate, tin, benzene, urea,
ammonia, water, zinc sulphide, graphite, rubidium, argon, silicon carbide.
5.Distinguish between(i) Hexagonal and monoclinic unit cells
ii) Face-centred and end-centred unit cells.
6.Ferric oxide crystallises in a hexagonal close-packed array of oxide ions with two out
of every three octahedral holes occupied by ferric ions. Derive the formula of the ferric
oxide.
7.Classify each of the following as being either a p-type or a n-type semiconductor:
(i) Ge doped with In (ii) Si doped with B.
8. In terms of band theory, what is the difference
(i) between a conductor and an insulator
(ii) between a conductor and a semiconductor?
9.Explain the following terms with suitable examples:
(i) Schottky defect (ii) Frenkel defect (iii) Interstitials and (iv) F-centres.
10. 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 cm3 of aluminium?
11.If NaCl is doped with 10–3 mol % of SrCl2, what is the concentration of cation
vacancies?
Explain the following with suitable examples:
(i) Ferromagnetism
(ii) Paramagnetism
(iii) Ferrimagnetism
(iv) Antiferromagnetism
(v) 12-16 and 13-15 group compounds.
12. Silver crystallizes in fcc lattice. If edge length of the cell is 4.07 x 10 –
density is 10.5 g cm– 3. Calculate the atomic mass of silver.
8
cm and
13.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?
14.Niobium crystallises in body-centred cubic structure. If density is 8.55 g cm –3,
calculate atomic radius of niobium using its atomic mass 93 u.
15. How will you distinguish between the following pairs of terms:
(i) Hexagonal close-packing and cubic close-packing?
(ii) Crystal lattice and unit cell?
(iii) Tetrahedral void and octahedral void?
16.Explain
(i) The basis of similarities and differences between metallic and ionic crystals.
(ii) Ionic solids are hard and brittle.
17.Calculate the efficiency of packing in case of a metal crystal for
(i) simple cubic
(ii) body-centred cubic
(iii) face-centred cubic (with the assumptions that atoms are touching each other).
18. Classify each of the following solids as ionic, metallic, molecular, network (covalent)
or amorphous.
(i) Tetra phosphorous decoxide (P4O10)
(ii) Ammonium phosphate (NH4)3PO4
(iii) SiC
(iv) I2
(v) P4
(vi) Plastic
(vii) Graphite
(viii) Brass
(ix) Rb
(x) LiBr
(xi) Si
19. Define the term solution.. How many types of solutions are formed? Write briefly
about each type with an example.
20. What type of deviation is shown by Ethyl alcohol and water solution.
21.a) State Raoult’s law for a solution of volatile liquids
b) A solution of urea in water has a b.p. of 373.128K.Calculate the F.P. of the
Same solution.(Kf for water = 1.86K/m , Kb = 0.52 K/m)
c) Which of the following has higher b.p. and why?
0.1M NaCl or 0.1M glucose
22.a)Differentiate between molarity and molality values for solution.What is the
effect of change in temperature on molarity?
b) What is reverse osmosis?
c) A solution prepared by dissolving 8.95 mg of a gene fragment in 35 ml of
Water has an O.P. of 0.335 Torr at 25 0 V Assuming that the gene fragment
is a non electrolyte,calculate its molar mass.
23.(a) define the following trms:
(i) Ideal solution
(ii) Azeotrope
(iii) Osmotic pressure
( b) a solution of glucose (C6H12O6) in water is labeled as 10 % by weight. What
would be the molality of the solution?
(molar mass of glucose = 180 g mol -1)
24. Define the term, mole fraction.
25. State Henry’s law and mention its two important applications
Jayashree S
PGT Chemistry