Summer vacation Holiday HW
Class XII (Chemistry)
Solve the following test papersTEST-A
M.M-10
Q1) Derive the packing efficiency of FCC unit cell. (2)
Q 2) Sodium crystallizes in a bcc unit cell.Calculate the approximate number of unit cells in 9.2g of
sodium. (At. Mass of = 23u)
(1)
Q 3) An element has a bcc structure with a cell edge of 288pm.The density of the element is 7.2 g/ cm3.
How many atoms are present in 208g of the element? (2)
Q 4) Analysis shows that nickel oxide has formula Ni0.98 O1.00 . What fraction of nickel exist as Ni2+ and
Ni3+ ions. (2)
Q 5) The density of chromium metal is 7.2 g/ cm3. If the unit cell has edge length 289pm . determine the
type of unit cell and also calculate the radius of an atom.( at mass= 52) (3)
TEST-B M.M-10
Q1) Derive the packing efficiency of BCC unit cell. (2)
Q2) Gold crystallizes in a fcc unit cell.Calculate the approximate number of unit cells in 2mg of gold. (At.
Mass of = 197u)
(1)
Q3) Rubidium crystallizes in BCC form with density of is 288pm. (At. Mass of Ag=108gm/mol) A copper
crystal has fcc lattice structure. Atomic radius of the copper atom is 128pm. Calculate the density of
copper (At. Mass=63.5 u)
(2)
Q4) An element has a fcc structure with a cell edge of 200pm.Calculate its density if 200g of this
element contain 24 × 103 atoms? (2)
Q5) An element X with an atomic mass of 60g/mol has density of 6.23 g/cm3. If the edge length of the
unit cell is 400pm.Identify the type of unit cell and also calculate the radius of an atom of this
element.(3)
TEST-C
M.M-10
Q1) ) Xenon crystallizes in a fcc unit cell. Calculate the approximate number of unit cells in 5g of xenon.
(At. Mass = 131u)
(1)
Q2) ) Aluminium crystallizes in a cubic close packed structure. Its metallic radius is 125 pm. (2)
(a) What is the length of the side of the unit cell?
(b) How many unit cells are there in 1.00 cm3 of aluminium?
Q3) Derive the packing efficiency of simple unit cell. (2)
Q4) Silver crystallizes in FCC form. What is the density of Ag if the distance between nearest Ag atoms is
288pm. (At. Mass of Ag=108gm/mol) (3)
Q5) The unit cell of an element of atomic mass 108 and density 10.5g/cm3 is a cube with edge length of
409pm. Find the structure of the crystal lattice. (2)
TEST-D
M.M-10
Q1) Derive the relationship of nearest neighbouring distance in (i) FCC (ii) BCC (3)
Q2) Gold(at radius= 0.144nm) crystallizes in a fcc unit cell.What is the length of the side of the unit
cell?(2)
Q3) An element(d= 6.8 g/cm3) has a bcc structure with cell edge of 290pm. Calculate the no. of atoms
present in 200g of the element. (2)
Q4)Tungsten crystallizes in a bcc unit cell. Calculate the approximate number of unit cells in 1.5g of
tungsten. (At. Mass = 184u)
(1)
Q5) Copper crystalises in a fcc unit cell with cell edge of 361pm and having density of 8.92g/cm3.
Calculate the molar mass of copper. (2)
Solve the following questions-
Q1 Predict the product of electrolysis of following in aqueous medium(Using neutral electrode)
Solution
Anode Reaction
Cathode Reaction
NaCl
Cu(NO3)2
AgNO3
CuCl2
H2SO4
HCl
Ni(NO3)
AuCl3
CuSO4
Mg(NO3)2
Q2 An aqueous solution containing 0.166g KI, was electrolyzed for two minutes with
a current of x amp and then treated with acidified KMnO4 solution the it required 20
ml of M/100 KMnO4. What is the value of x?
Q3 Why it is that acidified KMnO4 solution upon addition of a pinch of FeSO4
Turns to colorless? Explain with required reaction.
Q4 When 5 amp electricity for 193 seconds is passed in molten solution of nitrate of
a metal M (atomic mass =20 x), x gm of metal deposited at cathode. Calculate the pH
of 0.5 molar aqueous solution of hydroxide of M.
Q5 In an electrolytic cell of cell constant equal to 10 /cm, when aqueous solution of
CuSO4 of conductivity equal to 0.25 S/cm is electrolyzed for 4 hrs using a battery of
four volt, how much copper will deposit at cathode? (atomic mass of Cu = 63.5
g/mol)
Q6 Calculate the volume of gas at STP liberated at anode when .001M aqueous of
H2SO4 is electrolyzed between two platinum electrodes for 2 hrs with a current of 10
amp.
Q7. Calculate the molar conductivity of NH4OH at infinite dilution, if the molar
conductivities at infinite dilution of Ba(OH)2, NH4NO3 and Ba(NO3)2 are all x
S/cm2/mol.