# NEET and AIPMT NEET Chemistry States of Matter MCQ Questions Solved

NEET - 2016

Equal moles of hydrogen and oxygen gases are placed in 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?

(a) 1/4          (b) 3/8          (c) 1/2            (d) 1/8

Concept Videos :-

#6 | Graham's Law of Diffusion

Concept Questions :-

Graham's Law

(d) Given, number of moles of hydrogen (${\mathrm{n}}_{{\mathrm{H}}_{2}}$) and that of oxygen (${\mathrm{n}}_{{\mathrm{O}}_{2}}$) are equal.

... We have, the relation between ratio of number of moles escaped and ratio of molecular mass.

$\frac{{\mathrm{n}}_{{\mathrm{H}}_{2}}}{{\mathrm{n}}_{{\mathrm{O}}_{2}}}=\sqrt{\frac{{\mathrm{M}}_{{\mathrm{H}}_{2}}}{{\mathrm{M}}_{{\mathrm{O}}_{2}}}}$

where, M = Molecular mass of the molecule

$\frac{{\mathrm{n}}_{{\mathrm{O}}_{2}}}{{\mathrm{n}}_{{\mathrm{H}}_{2}}}=\sqrt{\frac{2}{32}}=\sqrt{\frac{1}{16}}$

$\frac{{\mathrm{n}}_{{\mathrm{O}}_{2}}}{0.5}$ = $\frac{1}{4}$

${\mathrm{n}}_{{\mathrm{O}}_{2}}$= 0.5/4 =1/8

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NEET - 2015

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

(a) high temperatures and low pressures

(b) low temperatures and high pressures

(c) high temperatures and high pressures

(d) low temperatures and low pressures

Concept Videos :-

#7 | Molecular Speeds & Kinetic Theory of Gases

Concept Questions :-

Kinetic Theory of Gas

Real gases show ideal gas behaviour at high temperature and low pressures.

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NEET - 2014

Equal masses of H2, O2 and methane have been taken in a container of volume V at temperature 27°C in identical conditions. The ratio of the volumes of gases H2: O2 : CH4 would be
(a) 8:16:1

(b) 16:8:1

(c) 16:1:2

(d) 8:1:2

Concept Videos :-

#3 | Ideal Gas Equation
#4 | Solved Examples on Ideas Gas Equation

Concept Questions :-

Ideal Gas Law

(c) According to Avogadro's hypothesis, Volume of a gas (V) $\propto$ number of moles (n)

Therefore, the ratio of the volumes of gases can be determined in terms of their moles. The ratio of volumes of H2: O2:methane (CH4)
is given by

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NEET - 2014

When 22.4 L of H2 (g) is mixed with 11.2 L of Cl2 (g), each at STP, the moles of HCl(g) formed is equal to

(a)  1 mole of HCl (g)

(b) 2 moles of HCl (g)

(c) 0.5 mole of HCl (g)

(d) 1.5 mole of HCl (g)

Concept Videos :-

#1 | Gas Laws
#2 | Charle's Law

Concept Questions :-

Gas Law

The given problem is related to the concept of stiochiometry of chemical equations. Thus, we have to convert the given volumes into their moles and then, identify the limiting reagent [possessing minimum number of moles and gets completely used up in the reaction].

The limiting reagent gives the moles of product formed in the reaction.

H2(g) + Cl2(g) $\to$2HCl (g)

Initial vol   22.4 L    11.2 L      2 mol

... 22.4 L volume at STP is occupied by,

Cl2 = 1 mole,

... 11.2 L volume will be occupied by,

Cl2 = 1x 11.2/22.4 mole = 0.5 mol

Thus, H2(g) + Cl2(g) $\to$2HCl (g)

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NEET - 2013

Maximum deviation from ideal gas is expected from:

(a) H2(g)

(b) N2(g)

(c) CH2(g)

(d) NH3(g)

Concept Videos :-

#7 | Molecular Speeds & Kinetic Theory of Gases

Concept Questions :-

Kinetic Theory of Gas

(d) Easily liquefiable gases like NH3, SO2 etc. exhibit maximum deviation from ideal gas as for them Z<<< 1 .

${\mathrm{CH}}_{4}$  also exhibits deviation but it is less as compared to NH3.

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NEET - 2011

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

(a) 0.8 atm

(b) 0.9 aim

(c) 1 atm

(d) 0.5 atm

Concept Videos :-

#5 | Dalton's Law of Partial Pressure

Concept Questions :-

Dalton's Law

"CO="N2

Pco = PN2

Given, Pco + PN2 = 1atm

or       2PN2 = 1 atm

or        PN2 = 0.5atm

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NEET - 2011

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

(a) 12.25 u
(b) 6.50 u
(c) 25.00 u
(d) 50.00 u

Concept Videos :-

#6 | Graham's Law of Diffusion

Concept Questions :-

Graham's Law

(a)

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NEET - 2011

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

(a) 2.8

(b) 4.0

(c) 1.4

(d) 2.0

Concept Videos :-

#7 | Molecular Speeds & Kinetic Theory of Gases

Concept Questions :-

Kinetic Theory of Gas

Average velocity = $\sqrt{\frac{8\mathrm{RT}}{\mathrm{\pi M}}}$

Vav $\mathrm{\alpha }$ $\sqrt{\mathrm{T}}$

or (Vav)2 / (Vav )1$\sqrt{\frac{2\mathrm{T}}{\mathrm{T}}}$ = 1.4

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NEET - 2008

If a gas expands at constant temperature, it indicates that

(a) kinetic energy of molecules decreases

(b) pressure of the gas increases

(c) kinetic energy of molecules remains the same

(d) number of the molecules of gas increases

Concept Videos :-

#7 | Molecular Speeds & Kinetic Theory of Gases

Concept Questions :-

Kinetic Theory of Gas

Key Idea: KE = 3/2RT

KE ∝ T

Here, the temperature of gas remains constant, hence kinetic energy of molecules remains the same.

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NEET - 2008

What volume of oxygen gas (O2) measured at 0°C and 1 atm, is needed to burn completely 1 L of propane gas (C3H8) measured under the same conditions?

(a) 7L

(b) 6L

(c) 5L

(d) 10L

Concept Videos :-

#1 | Gas Laws
#2 | Charle's Law

Concept Questions :-

Gas Law

Key Idea: Volume of a gas STP = 22.4L

To burn 22.4 L C3H8 the oxygen required is = 5 x 22.4 L

To burn 1 LC3H8 the oxygen required will be = 5 x 22.4 / 22.4 = 5L

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