States of Matter

Intermolecular forces are forces of attraction and repulsion between interacting particles that will include: Choose the most appropriate answer from the options given below:

1. A, B, C, D are correct
2. A, B, C, E are correct
3. A, C, D, E are correct
4. B, C, D, E are correct

Which amongst the following options is correct graphical representation of Boyle's law?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Which one is not correct mathematical equation for Dalton's Law of partial pressure? Here p = total pressure of gaseous mixture where pi = partial pressure of ith gas i = mole fraction of ith gas in gaseous mixture pi = pressure of ith gas in pure state

1. p = p1 + p2 + p3
2. p = n1 RTV + n2 RTV + n3 RTV
3. pi = i p
4. pi = i pi

A 10.0 L flask contains 64 g of oxygen at 27 C. (Assume O2 gas is behaving ideally). The pressure inside the flask in bar is (Given R = 0.0831 L bar K-1 mol-1)

1. 2.5
2. 498.6
3. 49.8
4. 4.9

A vessel contains 3.2 g of dioxygen gas at STP (273.15 K and 1 atm pressure). The gas is now transferred to another vessel at constant temperature, where pressure becomes one third of the original pressure. The volume of new vessel in L is : (Given : molar volume at STP is 22.4 L)

1. 67.2
2. 6.72
3. 2.24
4. 22.4

Four gas cylinders containing He, N2, CO2 and NH3 gases separately are gradually cooled from a temperature of 500 K. Which gas will liquefy first? (Given Tc in K – He : 5.3, N2 : 126, CO2 : 304.1 and NH3 : 405.5)

1. NH3
2. He
3. N2
4. CO2

Choose the correct option for graphical representation of Boyle's law, which shows a graph of pressure vs. volume of a gas at different temperatures :

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Choose the correct option for the total pressure (in atm.) in a mixture of 4 g O2 and 2 g H2 confined in a total volume of one litre at 0 C is : [Given R = 0.082 L atm mol-1 K-1, T = 273 K]

1. 26.02
2. 2.518
3. 2.602
4. 25.18

A mixture of N2 and Ar gases in a cylinder contains 7 g of N2 and 8 g of Ar. If the total pressure of the mixture of the gases in the cylinder is 27 bar, the partial pressure of N2 is : [Use atomic masses (in g mol-1) : N = 14, Ar = 40]

1. 12 bar
2. 15 bar
3. 18 bar
4. 9 bar

A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is -

1. Z < 1 and attractive forces are dominant
2. Z < 1 and repulsive forces are dominant
3. Z > 1 and attractive forces are dominant
4. Z > 1 and repulsive forces are dominant

Given van der Waals’ constant for NH3, H2, O2 and CO2 are respectively 4.17, 0.244, 1.36 and 3.59, which one of the following gases is most easily liquefied?

1. NH3
2. H2
3. O2
4. CO2

The correction factor ‘a’ to the ideal gas equation corresponds to

1. density of the gas molecules
2. volume of the gas molecules
3. electric field present between the gas molecules
4. forces of attraction between the gas molecules

Equal moles of hydrogen and oxygen gases are placed in a container with a pin-hole through which both can escape. What fraction of the oxygen escapes in the time required for one-half of the hydrogen to escape?

1. 3/8
2. 1/2
3. 1/8
4. 1/4

A gas such as carbon monoxide would be most likely to obey the ideal gas law at

1. low temperatures and high pressures
2. high temperatures and high pressures
3. low temperatures and low pressures
4. high temperatures and low pressures

Dipole-induced dipole interactions are present in which of the following pairs

1. HCl and He atoms
2. SiF4 and He atoms
3. H2O and alcohol
4. Cl2 and CCl4

Maximum deviation from ideal gas is expected from

1. CH4(g)
2. NH3(g)
3. H2(g)
4. N2(g)

What is the density of N2 gas at 227 C and 5.00 atm pressure? (R = 0.082 L atm K-1 mol-1)

1. 1.40 g/L
2. 2.81 g/L
3. 3.41 g/L
4. 0.29 g/L

A certain gas takes three times as long to effuse out as helium. Its molecular mass will be

1. 27 u
2. 36 u
3. 64 u
4. 9 u

For real gases van der Waals equation is written as (p + an2V2 )(V - nb) = nRT where a and b are van der Waals constants. Two sets of gases are (I) O2, CO2, H2 and He (II) CH4, O2 and H2 The gases given in set-I in increasing order of b and gases given in set-II in decreasing order of a, are arranged below. Select the correct order from the following

1. (I) He < H2 < CO2 < O2 (II) CH4 > H2 > O2
2. (I) O2 < He < H2 < CO2 (II) H2 > O2 > CH4
3. (I) H2 < He < O2 < CO2 (II) CH4 > O2 > H2
4. (I) H2 < O2 < He < CO2 (II) O2 > CH4 > H2

50 mL of each gas A and of gas B takes 150 and 200 seconds respectively for effusing through a pin hole under the similar conditions. If molecular mass of gas B is 36, the molecular mass of gas A will be

1. 96
2. 128.74
3. 20.25
4. 64.42

A bubble of air is underwater at temperature 15 and the pressure 1.5 bar. If the bubble rises to the surface where the temperature is 25 and the pressure is 1.0 bar, what will happen to the volume of the bubble?

1. Volume will become greater by a factor of 1.6.
2. Volume will become greater by a factor of 1.1.
3. Volume will become smaller by a factor of 0.70.
4. Volume will become greater by a factor of 2.5.

By what factor does the average velocity of a gaseous molecule increase when the temperature (in Kelvin) is doubled?

1. 2.0
2. 2.8
3. 4.0
4. 1.4

Two gases A and B having the same volume diffuse through a porous partition in 20 and 10 seconds respectively. The molecular mass of A is 49 u. Molecular mass of B will be

1. 50.00 u
2. 12.25 u
3. 6.50 u
4. 25.00 u

A gaseous mixture was prepared by taking equal moles of CO and N2. If the total pressure of the mixture was found to be 1 atmosphere, the partial pressure of the nitrogen (N2) in the mixture is

1. 0.5 atm
2. 0.8 atm
3. 0.9 atm
4. 1 atm

The pressure exerted by 6.0 g of methane gas in a 0.03 m3 vessel at 129 is (Atomic masses : C = 12.01, H = 1.01 and R = 8.314 J K-1 mol-1)

1. 215216 Pa
2. 13409 Pa
3. 41648 Pa
4. 31684 Pa

If a gas expands at constant temperature, it indicates that

1. kinetic energy of molecules remains the same
2. number of the molecules of gas increases
3. kinetic energy of molecules decreases
4. pressure of the gas increases

The surface tension of which of the following liquids is maximum ?

1. C2H5OH
2. CH3OH
3. H2O
4. C6H6

Van der Waals real gas acts as an ideal gas at which conditions?

1. High temperature, low pressure
2. Low temperature, high pressure
3. High temperature, high pressure
4. Low temperature, low pressure

The beans are cooked earlier in pressure cooker because

1. boiling point increases with increasing pressure
2. boiling point decreases with increasing pressure
3. extra pressure of pressure cooker softens the beans
4. internal energy is not lost while cooking in pressure cooker

Which of the following expressions correctly represents the relationship between the average molar kinetic energy, KE, of CO and N2 molecules at the same temperature?

1. KECO = KEN2
2. KECO > KEN2
3. KECO < KEN2
4. cannot be predicted unless volumes of the gases are given