1. Molarity =
n
v
L
n
2. Molality =
w
3 Ppm
3.
P
=
2
1
2
(K
g
)
w2 × 106
M a s s o f th e s o lu tio n
4. Mole fraction of solute =
n
1
n
+
2
n
2
5. Mole fraction of solvent =
6. Mass percentage of solute =
7 ) P
•P =
x
p
A
A
p
=
K
0
A
+ x
− p
0
p
0
H
x
B
A
.......
0
B
p
n2
=
n1 + n
2
n1
n1
+ n
2
w2 × 100
M a s s o f s o lu tio n
H
Henry’s
’ law
l
off gas solubility
l bilit
‐
Ideal binary solution of liquids
Raoult’s law.
•Raoult’s law of the solution of
a nonvolatile solute.
1 In 91% Ethanol by mass
1.
mass, the mole
fraction of Ethanol is :
a) 0.8
b) 0.7
c) 0.9
d) 0.6
Mole fraction of Ethanol =
91
91
46
+
46
ANS : ( a)
9
18
2
=
= 0.8
08
25
2.5
2) If ‘x’ molal solution of a compound in
benzene has mole fraction of solute
equal to 0.2, the value of ‘ x ‘ is :
a) 14
b) 3.2
c) 1.4
d) 2.0
1000
x moles → 1 Kg of Benzene =
12.5 moles.
78
M.F. of Solute =
0.2 ⇒ M. F . of Benzene = 0.8
0.8 moles of Benzene → 0.2 moles of solute
12.5 moles
ANS :
(b)
0.2 × 12.5
→
3.2
0.8
3) The volumes of 4 M HCl and 10M HCl
required to prepare 1 litre of 6 M HCl is :
a) 0.75L
0 75L of 4 M HCl + 0.25L
0 25L of 10 HCl
b)0.67L of 4 M HCl +0.33L of 10M HCl
c) 0.25L of 4 M HCl +0.75L of 10 M HCl
d) 0.80L of 4 M HCl + 0.20 L of 10 M HCl
4 x + 10 (1 − x ) = 6 × 1
ANS : (b)
2
∴x =
3
4) Which of the following aqueous
g
boiling
g
Solution should have the highest
point ?
a) 1 M NaOH
b) 1 M Na2SO4
c) 1 M NH4NO3
d) 1 M KNO3
ANS : b
5. The values of Vant Hoff
Hoff’s
s factor for
KCl, NaCl and K2SO4 are respectively
a)) 2,2,1
22
b) 2
2,2,3
23
c)) 1
1, 1
1, 2
d) 1
1, 2
2,1
1
ANS : (b)
6) 4 L of 0.02M solution of NaCl was diluted
by adding 1L of water. The molarity of the
solution is :
a)
0.004
b) 0.008
c)
0.012
d) 0.016
M 1V1 = M 2V 2
0 .0 2 × 4 = M
∴ M 2 = 0.016
ANS : ( d )
2
× 5
7) The Molarity of HCl if the density of
the Solution is 1.825g/cc is :
a)) 25
b) 50
c)) 30
d) 40
Molarity =
1 825
1.825
36.5
−3
1×10
ANS : ( b )
= 50
8) 12g of urea is dissolved in 1L of the
Solution and 68.4g of Sucrose was dissolved in 1L
off the
h solution.
l i
Th
The relative
l i llowering
i
off vapour
pressure of urea solution is :
a)
b)
c)
d)
greater than Sucrose solution
d bl that
double
th t off Sucrose
S
solution
l ti
less than Sucrose solution
equall to
t that
th t off S
Sucrose solution
l ti
12
Molarity
y of urea =
60
1
Molarity of Sucrose =
ANS : (d )
= 0.2 M
68.4
342
1
= 0.2M
9) Ethylene glycol is used as
antifreeze in a cold climate.
climate Mass
of ethylene glycol to be dissolved in
4 Kg of water to prevent it from
freezing at -5.60 will be
⎡⎣ K f = 1.86 K Kg mol −1 ⎦⎤
) 500g
b) 624g
c) 744 g
d) 800g
a
∆Tf = K f × m
5.6 = 1.86 × m
m = 3. ⇒ 3 moles / Kg
oor 12 moles / 4 Kg
g
12 × 62 = 74Kg
CH2OH M = 62
CH2OH
ANS : ( c )
∆T
10) If Sodium sulphate is completely
ionized in solution, the value of
= 1.86 )
when 0.01 mol of Sod sulphate( K is
dissolved in 1 kg of water is
f
f
a)
0.0744
b) 0.0186
c)
0.0372
d) 0.0558
∆Tf = i K f m
= 3 × 1.86 × 0.01
ANS : ( d )
= 0.0558
11)The elevation in the B.pt of a solution
of 13.44g
13 44g of CuCl2 in 1kg of water is
( Kb=0.52K kg mol-1 and Mol mass of
CuCl2=134.4)
=134 4)
a)) 0.05
b)) 0.1
c)) 0.16
d)) 0.21
∆Tb = i Kbm
13.44
13
44
= 3×0.52×
= 0.16
134 4×1
134.4
ANS : ( c )
12)The molarity of the resulting
S l ti
Solution
obtained
bt i d b
by mixing
i i
4L off 0
0.2
2M
NaOH with 2L of 0.5M NaoH is
a) 0.9 M
c) 1.8M
b) 0.3M
d) 0.18 M
4
×
02
0.2
+
2
×
05
0.5
(
)
(
)
MV
MV
+
1 1
2 2
=
= 0.3M
V1 +V2
6
ANS : (b)
( )
13)Conc HNO3 is 70% by mass. How many
gms of conc HNO3 should be used to
prepare
p
epa e 250mL
50
o
of 2M HNO
O3 ?
a)) 45g
45
b) 90g
90
c)) 70g
70
d) 54g
54
Molarity =
W2
o r W 2 = M o la rity × M 2 × V L
M 2 × VL
= 2 × 63 × 0.25
0 25 = 31
31.5g
5g
100
M off HNO3 =
Mass
× 31.5
31 5 = 45g
70
ANS : (a)
14) 5 ml of acetone is mixed with 100ml
of H2O.
O The vapour pressure of water
above the solution is
a) equal to the V.P. of pure water
b)equal
)
to the V.P. off solution
c) less than the V.P. of pure water
d)
d)More
than
h
the
h V.P. off pure H2O
ANS : C
15) At a given temp, the vapour
pressures of two liquids
p
q
A and B are 120
and 180 mm of Hg respectively. The V.P.
of the ideal solution containing
g 2 moles of
A and 3 moles of B will be
a) 156mm
b) 145mm
c) 150mm
d) 108mm
P = X
A
P
0
A
+ X
B
P
0
B
⎛ 2
⎞ ⎛ 3
⎞
= ⎜ × 120 ⎟ + ⎜ × 180 ⎟ = 156m m
⎝ 5
⎠ ⎝ 5
⎠
ANS : ( a )
16) Negative deviation from Raoult’s law is
observed in which of the following binary
liquid mixtures ?
a) Ethanol & acetone
b) Benzene & Toluene
c) Chloro Ethane & Bromo Ethane
d) Acetone and Chloroform
ANS : d
17)18g of glucose is added to 178.2 g of
water. The vapour pressure of water for
this solution at 1000C is
a)76 Torr
b) 752
752.4
4 Torr
c) 759 Torr
d) 7
7.6
6 Torr
18g of Glucose =
178.2g of water =
18
= 0 .1 m o le
180
1 7 8 .2
= 9 .9 m o le s
18
P0 − P
0 .1
760 − P
∴
=
⇒
= 0 .0 1
0
P
10
760
∴
P
= 7 6 0 − 7 .6 = 7 5 2 .4
ANS : b
18.The
8. e osmotic
os ot c pressure
p essu e o
of a so
solution
ut o
at 00C is 4 atmos.The osmotic pressure
at 546 K is
a) 4atm
c) 8atm
b) 2atm
d) 1atm
π
π
1
2
T1
=
T2
ANS : c
19) An aqueous solution of KI is 1 molal.
g will cause
Which of the following
the vapour pressure of the solution to
increase?
a) Addition of water
b)Addition of NaCl
c) Addition of Na2SO4
d)Addition of Kl solution
ANS : ( a )
20) Th
The average osmotic
ti pressure off
human blood is 7.8 bar at 370C. What is
n of
th Conc
the
C
fN
NaCl
Cl that
th t could
ld be
b iinjected
j t d
into the blood ?
a)) 0.15M
0 15M
b) 0.30M
0 30M
c)) 0
0.60M
60M
d) 0
0.45M
45M
π
7.8
78
π =iCRT ∴C = =
= 0.1519
iRT 2×0.083×310
ANS : ( a )
21) A
solution of urea boils at 100.180C at
1 atmos. If Kf and Kb for water are 1.86
and 0.52 K kg Mol-1 respectively, the
above solution will freeze at
a)-6.540C
b) -0.6540C
c) 6.540C
d) 0.6540C
K
f
Kb
=
∆T f
∆ Tb
ANS : b
11.86
86 ∆Tf
=
= 0.65
0 52 00.18
0.52
18
22.Solutions
22
Solutions A,
A B,
B C and D are espectively
0.1M Glucose, 0.05M NaCl, 0.05M
BaCl2 and 0.1M
0 1M AlCl3. Which one of the
following pairs is isotonic ?
a)A & B
b) B & C
c) A & D
d) A & C
ANS : (a )
23) 0.1M NaCl and 0.05M BaCl2 are
separated by S.P.M.
S P M which of the
following is true ?
a) No movement across the membrane
b) Water
Wate flows
ows into
to NaCl
aC so
solution
ut o
c) Water flows into BaCl2 solu tion
Osmotic
ot c Pressure
ess e of
o 0.
0.1M NaCl
aC is
s
d)) Os
lower than that of BaCl2
ANS : (c )
24) If two liquids A and B havePA0 : PB0 = 1: 2
Then the molefraction of A in Vapours is
(M.F’s of A & B are in the ratio of 1:2)
a)0.33
b) 0.25
c) 0.52
d) 0.2
P = x A p + xB p
0
A
(1 × 1 ) + ( 2
=5
× 2
0
B
)
PA 1
= = 0.2
M.F. of A in vapour phase =
P 5
ANS : ( d )