Home
Class 12
PHYSICS
Modern vacuum pumps permit to pressures ...

Modern vacuum pumps permit to pressures down to `p = 4.10^-15 atm` to be reached at room temperatures. Assuming that the gas exhausted is nitrogen, find the number of its molecules per `1 cm^3` and the mean distance between them at this pressure.

Text Solution

Verified by Experts

From the formula `p = n k T`
`n = (p)/(kT) = (4 xx 10^-15 xx 1.01 xx 10^5)/(1.38 xx 10^-23 xx 300) per m^3`
=`1 xx 10^11 per m^3 = 10^5 per c.c`
Mean distance between molecules
`(10^-5 c.c)^(1//3) = 10^(1//3) xx 10^-2 cm = 0.2 mm`.
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • THERMODYNAMICS AND MOLECULAR PHYSICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise The Second Law Of Thermodynamics - Entropy|47 Videos

  • THERMODYNAMICS AND MOLECULAR PHYSICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise Liquids Capillary Effects|25 Videos

  • THERMODYNAMICS AND MOLECULAR PHYSICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise The First Law Of Thermodynamics - Heat Capacity|36 Videos

  • PHYSICAL FUNDAMENTALS OF MECHANICS

    IE IRODOV, LA SENA & SS KROTOV|Exercise Relativistic Mechanics|49 Videos

Similar Questions

Explore conceptually related problems

Find the number of molecules in 1cm^(3) of an ideal gas at o^(@) and at a pressure of 10^(-5)mm of mercury.

The total number of air molecules in a room of capacity 20 m^(3) at a temperature of 27^(@)C and 1 atm pressure is

Knowledge Check

  • The number of molecules in 1 cm^(3) of an ideal gas at 0^(@)C and at a pressure of 10^(–5) mm of mercury is –

    A
    `2.7xx10^(11)`
    B
    `3.5xx10^(11)`
    C
    `6.0xx10^(23)`
    D
    `6xx10^(12)`

  • In a very good vacuum system in the laboratory, the vacuum attained was 10^-13 atm . If the temperature of the system was 300 K , the number of molecules present in a volume of 1 cm^3 is.

    A
    `2.4 xx 10^6`
    B
    `24`
    C
    `2.4 xx 10^9`
    D
    zero

    • Similar Questions

    Explore conceptually related problems

    The lowest pressure (the best vacuum) that can be created in laboratory at 27^(@)C is 10^(-11)mm of Hg. At this pressure,the number of ideal gas molecules per cm^(3) will be :

    An electronic vacuum tube was sealed off during an experiment at a pressure of 8.2xx10^(-10) atm at 27^(@)C The volume of the tube was 30dm^(3) . The number of gas molecules remaining in the tube are

    A vessel of volume , V = 5.0 litre contains 1.4 g of nitrogen at a temperature T = 1800 K . Find the pressure of the gas if 30% of its molecules are dissociated into atoms into atmos at this temperature.

    The volume of a gas at pressure 1.2 xx 10^(7) Nm^(-2) and temperature 127^(@)C is 2.0 litre. Find the number of molecules in the gas.

    Pressure of monoatomic gas in a container is 2 atm. Average KE per molecule is 2 x 10-9J. Volume of gas is 1litre. Find number of molecules of gas present in the container

    What is mean free path for oxygen molecule at room temperature (300K)and at atmospheric pressure of 1atm? (given diameter of oxygen molecule is 2.9times10^(-10)m)

    Home
    Profile