A gas is at temperature 80 ° C and pressure 5 × 10 - 10 N / m 2 . What is the number of molecules per m 3 .

Temperature of gas ( T ) = 80 ° C = ( 80 + 273 ) K = 353 K Pressure of gas ( P ) = 5 × 10 - 10 N / m 2 Boltzmann ' s constant ( k ) = 1 . 38 × 10 - 23 J / K V = 1 m 3 Number of molecules , n = P V k T = 5 × 10 - 10 × 1 1 . 38 × 10 - 23 × 353 n = 5 × 10 - 10 487 . 14 × 10 - 23 = 0 . 01026 × 10 13 n = 1 . 02 × 10 11

If 10 20 oxygen molecules per second strike 4 cm 2 of wall at an angle of 30 ° with the normal when moving at a speed of 2 × 10 3 m / s , find the pressure exerted on the wall. Mass of one oxygen atom = 2 . 67 × 10 - 26 k g

Mass of O 2 atom striking wall per second; m = 16 × 10 20 × 2 . 67 × 10 - 26 m = 42 . 72 × 10 - 6 kg Momentum of the O 2 molecule; P = m v = 42 . 72 × 10 - 6 × 2 × 10 3 P = 85 . 44 × 10 - 3 kgm / s Momentum normal to the wall at angle 30 ° F = 85 . 44 × 10 - 3 × cos 30 ° F = 73 . 99104 × 10 - 3 kgm / s Pressure = F A = 73 . 99104 × 10 - 3 4 × 10 - 2 2 Pressure = 4 . 62444 × 10 Pressure = 46 . 2 N / m 2

E M B I B E

Physics Standard 11 Vol II>Chapter 9 - Kinetic Theory of Gases>EVALUATION>Q III

EASY

11th Tamil Nadu Board

IMPORTANT

Earn 100

Describe the Brownian motion.

Important Questions on Kinetic Theory of Gases

MEDIUM

11th Tamil Nadu Board

IMPORTANT

Physics Standard 11 Vol II>Chapter 9 - Kinetic Theory of Gases>EVALUATION>Q IV

A fresh air is composed of nitrogen $N_{2} (78 %)$ and oxygen $O_{2} (21 %)$ . Find the rms speed of $N_{2} and O_{2} at 20 ° C .$

$Absolute temperature, T = 20 ° C, Gas constant R = 8.32 {Jmol}^{- 1} K^{- 1}, For Nitrogen : molar mass = 28 \times 10^{- 3} kg / mol, For Oxygen : molar mass = 32 \times 10^{- 3} kg / mol$

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11th Tamil Nadu Board

IMPORTANT

Physics Standard 11 Vol II>Chapter 9 - Kinetic Theory of Gases>EVALUATION>Q IV

If the rms speed of methane gas in the Jupiter's atmosphere is

471.8 m / s

, show that the surface temperature of Jupiter is sub-zero.

EASY

11th Tamil Nadu Board

IMPORTANT

Physics Standard 11 Vol II>Chapter 9 - Kinetic Theory of Gases>EVALUATION>Q IV

Calculate the temperature at which the rms velocity of a gas triples its value at S.T.P.

EASY

11th Tamil Nadu Board

IMPORTANT

Physics Standard 11 Vol II>Chapter 9 - Kinetic Theory of Gases>EVALUATION>Q IV

A gas is at temperature

80 ° C

and pressure

5 \times 10^{- 10} N / m^{2} .

What is the number of molecules per

m^{3} .

EASY

11th Tamil Nadu Board

IMPORTANT

Physics Standard 11 Vol II>Chapter 9 - Kinetic Theory of Gases>EVALUATION>Q IV

If

10^{20}

oxygen molecules per second strike

4 {cm}^{2}

of wall at an angle of

30 °

with the normal when moving at a speed of

2 \times 10^{3} m / s

, find the pressure exerted on the wall. Mass of one oxygen atom =

2.67 \times 10^{- 26} k g

EASY

11th Tamil Nadu Board

IMPORTANT

Physics Standard 11 Vol II>Chapter 9 - Kinetic Theory of Gases>EVALUATION>Q IV

During an adiabatic process, the pressure of a mixture of monatomic and diatomic gases is found to be proportional to the cube of the temperature. Find the value of