States of Matter Class 11 MCQ Online Test With Answers Questions

Answer: (c) 0.4 atm
Explanation:
Vapour pressure depends on T only and it does not depend on container volume.

Answer: (c) Alcohol, Petrol, Water
Explanation:
The vapour pressure of the liquid is inversely proportional to the magnitude of the intermolecular forces of attraction present. Based on this, the liquid with higher vapour pressure in the different pairs is: (a) Alcohol, (b) Petrol, (c) Water.

Answer: (a) 64.0
Explanation:
Let rate of diffusion of gas x, r₁ = a
Therefore, rate of diffusion of methane, r₂ = 2 a
According to Grahams Law of Diffusion
(\(\frac {r_1}{r_2}\)) = (\(\sqrt{\frac {M_2}{M_1}}\))
M₁ = Molecular mass of gas x
M₂ = Molecular mass of Methane = 16 g
Therefore, (\(\frac {a}{2a}\)) = (\(\sqrt{\frac {16}{M_2}}\))
Squaring both the sides, (\(\frac {1}{4}\)) = (\(\frac {16}{M_2}\))
or, M₂ = 16 × 4 = 64 g

Answer: (c) Gas
Explanation:
Of the three states of matter, the gaseous state is the simplest and shows greatest uniformity in behaviour. Gases show almost similar behaviour irrespective of their chemical nature. This state is characterized by:
Gases maintain neither the volume nor the shape. They completely fill the container in which they are placed.

They expand appreciably on heating. Gases are highly compressible. The volume of the gas decreases when the pressure increases. They diffuse rapidly into space. Gases exert equal pressure in all directions.
All gases are colourless except a few e.g. chlorine (greenish yellow) bromine (reddish brown), nitrogen dioxide (reddish brown)

The behaviour of gases can be described by certain quantitative relationships called gas laws. They give the relationship between mass, pressure, volume and temperature.

Answer: (a) Attract one another
Explanation:
The basic concept of the kinetic-molecular theory give us the information why real gases deviate from ideal behavior. The molecules of an ideal gas are assumed to occupy no space and have no attractions for one another. Real molecules, however, do have finite volumes, and they do attract one another. So, a gas deviates from ideal behavior at a high pressure because its molecules attract one another.

Answer: (d) Units of Volume,Temperature and Pressure
Explanation:
The value of the gas constant R depends on the units used for pressure, volume and temperature.

Answer: (d) D
Explanation:
V_c = 3b = 3 × 4N × (4/3) πr³

Answer: (d) Mass of the gas cannot be determined by weighing a container in which it is contained
Explanation:
Mass of the gas = mass of the cylinder including gas – mass of empty cylinder. So mass of a gas can be determined by weighing the container in which it is enclosed. Thus, the statement (d) is wrong for gases.

Answer: (c) Volume occupied by the molecules
Explanation:
In van der Waals equation of state of the gas law, the constant b is a measure of the volume occupied by the molecules. It gives the effective size of the gas molecules. The greater value of b indicates a larger size of the molecules and smaller compressible volume.

Answer: (a) 30 L
Explanation:
According to the ideal gas equation, we have
PV = nRT
​PV = (\(\frac {w}{M}\)) RT
​V = ​ (\(\frac {w}{M}\)) (\(\frac {RT}{P}\))
Given values are:
w = 2.8 g
M = Molar mass of CO = 28 g mol^-1
T = 27°C = (273 + 27) = 300 K
P = 0.821 atm
R = 0.0821 L atm mol^-1 K^-1
Putting the values in the formula we get :
V = (2.8 g /28 g mol^-1) × (0.0821 L atm mol^-1 K^-1) × (300 K)/(0.821 atm)
= 3 L

Answer: (a) 20 × 150
Explanation:
At constant T, P₁V₁ = P₂V₂
1 × 20 = P₂ × 50;
P₂ = (\(\frac {20}{ 50}\)) × 1

Answer: (b) 11

Answer: (b) Liquid
Explanation:
In a liquid, particles will flow or glide over one another, but stay toward the bottom of the container. The attractive forces between particles are strong enough to hold a specific volume but not strong enough to keep the molecules sliding over each other.

Answer: (b) Capillary Action
Explanation:
Capillarity, rise or depression of a liquid in a small passage such as a tube of small cross-sectional area, like the spaces between the fibres of a towel or the openings in a porous material. Capillarity is not limited to the vertical direction. Water is drawn into the fibres of a towel, no matter how the towel is oriented.

Liquids that rise in small-bore tubes inserted into the liquid are said to wet the tube, whereas liquids that are depressed within thin tubes below the surface of the surrounding liquid do not wet the tube. Water is a liquid that wets glass capillary tubes; mercury is one that does not. When wetting does not occur, capillarity does not occur.

Capillarity is the result of surface, or interfacial, forces. The rise of water in a thin tube inserted in water is caused by forces of attraction between the molecules of water and the glass walls and among the molecules of water themselves. These attractive forces just balance the force of gravity of the column of water that has risen to a characteristic height. The narrower the bore of the capillary tube, the higher the water rises. Mercury, conversely, is depressed to a greater degree, the narrower the bore.

Answer: (d) Kinetic Molecular Theory
Explanation:
The kinetic molecular theory (KMT) is a simple microscopic model that effectively explains the gas laws described in previous modules of this chapter. This theory is based on the following five postulates described here. (Note: The term “molecule” will be used to refer to the individual chemical species that compose the gas, although some gases are composed of atomic species, for example, the noble gases.)

Gases are composed of molecules that are in continuous motion, travelling in straight lines and changing direction only when they collide with other molecules or with the walls of a container.
The molecules composing the gas are negligibly small compared to the distances between them.
The pressure exerted by a gas in a container results from collisions between the gas molecules and the container walls.

Gas molecules exert no attractive or repulsive forces on each other or the container walls; therefore, their collisions are elastic (do not involve a loss of energy).
The average kinetic energy of the gas molecules is proportional to the kelvin temperature of the gas.

Answer: (b) Surface Tension
Explanation:
Raindrops take up the spherical shape due to the surface tension of water which is caused due to the tendency of water molecules to stick together. The spherical shape is having the least possible surface area due to which it can resist any of the external force in the atmosphere.

Answer: (b) Grahams Law
Explanation:
Grahams law states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight. In the same conditions of temperature and pressure, the molar mass is proportional to the mass density. Therefore the rate of diffusion of different gases is inversely proportional to the square root of their mass densities.
r α (\(\sqrt{\frac {1}{d}}\))
and r α (\(\sqrt{\frac {1}{M}}\))

Answer: (a) Boyles law
Explanation:
In 1662 Robert Boyle studied the relationship between volume and pressure of a gas of fixed amount at constant temperature. He observed that volume of a given mass of a gas is inversely proportional to its pressure at a constant temperature. Boyles law, published in 1662, states that, at constant temperature, the product of the pressure and volume of a given mass of an ideal gas in a closed system is always constant. It can be verified experimentally using a pressure gauge and a variable volume container. It can also be derived from the kinetic theory of gases: if a container, with a fixed number of molecules inside, is reduced in volume, more molecules will strike a given area of the sides of the container per unit time, causing a greater pressure.
A statement of Boyles law is as follows:
The volume of a given mass of a gas is inversely related to pressure when the temperature is constant.​
V ∝ (\(\frac {1}{P}\)) meaning “Volume is inversely proportional to Pressure”, or
P ∝ (\(\frac {1}{V}\)) meaning “Pressure is inversely proportional to Volume”, or
where P is the pressure, and V is the volume of a gas, and k₁ is the constant in this equation.

Answer: (a) 2 : 1
Explanation:
According to Grahams law
(\(\frac {r_1}{r_2}\)) = (\(\sqrt{\frac {M_1}{M_2}}\))
(r_He/r_CH4) = (\(\sqrt{\frac {16}{4}}\))
= (\(\frac {1}{2}\))

Answer: (a) The particles move faster.
Explanation:
There is a great deal of empty space between particles, which have a lot of kinetic energy. The particles move very fast and collide into one another when the gas is heated up, causing them to diffuse, or spread out, until they are evenly distributed throughout the volume of the container.