Chemistry - States of Matter
Exam Duration: 45 Mins Total Questions : 30
When the pressure is not too high the van der Waal's equation reduces to
- (a)
PV = RT - a/V
- (b)
PV = RT + Pb
- (c)
PV = RT - a/V2
- (d)
PV = RT
Equal masses of SO2 and O2 are mixed in an empty container at \({ 27 }^{ \circ }C\). The total pressure exerted by SO2 gas is
- (a)
0.20 atm
- (b)
0.33 atm
- (c)
0.67 atm
- (d)
1 atm
Two flasks A and B each 500 ml capacity contain helium and hydrogen respectively at \({ 27 }^{ \circ }C\) and 1 atmospheric pressure. The flask A contains
- (a)
the same number of atoms as in B
- (b)
the same weight of the gas as in B
- (c)
double the number of atoms as in B
- (d)
half the number of atoms as in B
The vapour density of ozone would be
- (a)
24
- (b)
96
- (c)
48
- (d)
16
The correct representation of van der Waal's equation is
- (a)
PV = RT
- (b)
(P+a/V2)(V-b) = RT
- (c)
(P-a/V2) (V+b)
- (d)
PV = 1/3 mnV2
The rates of diffusion of SO2, CO2, PCl3, and SO3 are in the order
- (a)
\(PCl_3>SO_3>SO_2>CO_2\)
- (b)
\(CO_2>SO_2>PCl_3>SO_3\)
- (c)
\(SO_2>SO_3>PCl_3>CO_2\)
- (d)
\(CO_2>SO_2>SO_3>PCl_3\)
180ml of hydrogen take 15 min. to diffuse. Under the same conditions 120 ml sulphur dioxide (mol. mass =64) takes 20 min. The moleculer mass of hydrocarbon is
- (a)
16
- (b)
32
- (c)
48
- (d)
64
The ratio of the rate of diffusion of oxygen to that of hydrogen gas is
- (a)
4:1
- (b)
1:4
- (c)
1:2
- (d)
2:1
A vessel is filled with a mixture of equal masses of oxygen and nitrogen. What is the ratio of partial pressures of oxygen and nitrogen?
- (a)
\({ P }_{ { 0 }_{ 2 } }=0.5\quad { P }_{ { N }_{ 2 } }\)
- (b)
\({ P }_{ { 0 }_{ 2 } }=0.875\quad { P }_{ { N }_{ 2 } }\)
- (c)
\({ P }_{ { 0 }_{ 2 } }= { P }_{ { N }_{ 2 } }\)
- (d)
\({ P }_{ { 0 }_{ 2 } }=1.14\quad { P }_{ { N }_{ 2 } }\)
The inversion temperature for a van der Waal's gas is given by
- (a)
\({ T }_{ i }=\frac { a }{ Rb } \)
- (b)
\({ T }_{ i }=\frac { a }{ 2Rb } \)
- (c)
\({ T }_{ i }=\frac { 2a }{ Rb } \)
- (d)
NONE OF THESE
A gas mixture contains 4 gm of H2, 56 gm of N2, 64 gm of O2 and 88 gm of CO2. The mole fraction of N2 in the mixture is
- (a)
0.25
- (b)
0.5
- (c)
0.66
- (d)
1.0
The molecule of SO2 is four times heavier than the molecule of CH4. The root mean square velocity for CH4 molecule is
- (a)
one-fourth that of SO2 molecule
- (b)
equal to that of SO2 molecule
- (c)
twice that of SO2 molecule
- (d)
four times that of SO2 molecule
Which of the following substances has the highest m.p.?
- (a)
NaCl
- (b)
MgO
- (c)
KCl
- (d)
BaO
Sodium chloride crystallises in the face centred cubic structure. What is the total sodium ions per unit cell in sodium chloride?
- (a)
2
- (b)
4
- (c)
6
- (d)
8
Which of the following is isotropic?
- (a)
alcohol
- (b)
copper sulphate
- (c)
calcium oxide
- (d)
rhombic sulphur
The crystal system available depending on three intersecting edges and the three angles between these axes are
- (a)
3
- (b)
4
- (c)
7
- (d)
14
Air is a mixture of N2 and O2 mainly in the ratio of 4 : 1. Five litres of CH4 was burnt in excess of air according to the reaction
\(CH_4+2O_2\rightarrow CO_2+2H_2O\)
The volume of air used during this process would be
- (a)
10 litres
- (b)
20 litres
- (c)
40 litres
- (d)
50 litres
In a solid AB having the NaCl structure, 'A' atoms occupy the corners of the unit cells. If all the face centred atoms along one of the axes are removed, then the resultant stoichiometry of the solid is
- (a)
AB2
- (b)
A2B
- (c)
A4B3
- (d)
A3B4
When the temperature is increased, surface tension of water
- (a)
increases
- (b)
decreases
- (c)
remains constant
- (d)
shows irregular behaviour
A cubic solid is made of two elements, P and Q atoms. Atoms Q are at the corners of the cube and P at the body centre. The formula of the compound would be?
- (a)
PQ
- (b)
\(\frac { 1 }{ 2 } PQ\)
- (c)
PQ2
- (d)
P2Q
The density of a gas at \({ 27 }^{ \circ }C\) and 1 atm is d. Pressure remaining constant, at which of the following temperatures will its density become 0.75 d?
- (a)
\({ 20 }^{ \circ }C\)
- (b)
\({ 30 }^{ \circ }C\)
- (c)
\(400\ K\)
- (d)
\(300\ K\)
Select one correct statement. In the gas equation PV = nRT
- (a)
n is the number of molecules of a gas
- (b)
n moles of the gas have a volume V
- (c)
V denotes volume of one mole of the gas
- (d)
P is the pressure of the gas when only one mole of gas is present
3.2 g of oxygen (at wt. = 16) and 0.2 g of hydrogen (at wt. = 1) are placed in a 1.12 L flask at \({ 0 }^{ \circ }C\). The total pressure of the gas mixture will be
- (a)
1 atm
- (b)
4 atm
- (c)
3 atm
- (d)
2 atm
Six litres of an ideal gas is at STP. The temperature of this gas was first raised to \({ 273 }^{ \circ }C\) at a constant pressure and then the pressure aws changed to 4 atm at constant temperature. The final volume of the gas would be
- (a)
2 L
- (b)
3 L
- (c)
6 L
- (d)
12 L
All the three states of matter e.g., water, ice and vapour exist simultaneously at
- (a)
4.58 mm and \({ 0.0098 }^{ \circ }C\)
- (b)
273 K and 1 atm
- (c)
6.48 mm and \({ 0.0148 }^{ \circ }C\)
- (d)
387 mm and \({ 0.0891 }^{ \circ }C\)
If the absolute temperature of a gas having volume V cm3 is doubled and the pressure is reduced to half, the final volume would be
- (a)
2V
- (b)
4V
- (c)
8V
- (d)
16V
An open vessel containing air is heated from \({ 27 }^{ \circ }C\) to \({ 127 }^{ \circ }C\). The fraction of air originally present which goes out of it is
- (a)
\(1\over 8\)
- (b)
\(1\over 4\)
- (c)
\(2\over 3\)
- (d)
\(1\over 12\)
Density of a gas is found to be 5.40 g dm-3 at \({ 27 }^{ \circ }C\) at 2 bar pressure. Its density at STP would be
- (a)
2.4 g dm-3
- (b)
3 g dm-3
- (c)
2 g dm-3
- (d)
NONE OF THESE
The compressibility factor for an ideal gas is
- (a)
1.0
- (b)
1.2
- (c)
1.5
- (d)
\(\infty \)