Advertisements
Advertisements
प्रश्न
Explain, on the basis of the kinetic theory of gases, how the pressure of a gas changes if its volume is reduced at a constant temperature.
Advertisements
उत्तर १
- At constant temperature, a gas's average kinetic energy per molecule remains constant.
- When a gas's volume is lowered at a constant temperature, the number of gas molecules colliding with the container's walls per unit time increases.
- The momentum transferred per unit time per unit area, i.e. the force exerted by the gas on the walls, increases as a result.
- As a result, the gas pressure rises.
उत्तर २
Let P - be the pressure exerted by the gas
V - be the volume of the gas
N - be the number of molecule of gas
m - be the mass of each molecule of gas.
∴ Total mass of the gas, M = Nm.
From kinetic theory of gases,
`P = (1/3) (Nm)/V barv^2`
∴ Pressure exerted by gas in an enclosed vessel is
`P = 2/3 N/V (1/2mbarv^2)`
But `1/2mbarv^2` = (Kinetic energy at constant temperature)
N is number which is also constant.
∴ `P = "Constant"/V`
∴ `P ∝ 1/V`
As a result, at constant temperature, increasing the pressure of the gas reduces its volume.
APPEARS IN
संबंधित प्रश्न
Do you expect the gas in a cooking gas cylinder to obey the ideal gas equation?
Can we define the temperature of (a) vacuum, (b) a single molecule?
Comment on the following statement: the temperature of all the molecules in a sample of a gas is the same.
Consider a gas of neutrons. Do you expect it to behave much better as an ideal gas as compared to hydrogen gas at the same pressure and temperature?
If the molecules were not allowed to collide among themselves, would you expect more evaporation or less evaporation?
The mean square speed of the molecules of a gas at absolute temperature T is proportional to
Find the number of molecules of an ideal gas in a volume of 1.000 cm3 at STP.
An ideal gas is trapped between a mercury column and the closed-end of a narrow vertical tube of uniform base containing the column. The upper end of the tube is open to the atmosphere. The atmospheric pressure equals 76 cm of mercury. The lengths of the mercury column and the trapped air column are 20 cm and 43 cm respectively. What will be the length of the air column when the tube is tilted slowly in a vertical plane through an angle of 60°? Assume the temperature to remain constant.
The condition of air in a closed room is described as follows. Temperature = 25°C, relative humidity = 60%, pressure = 104 kPa. If all the water vapour is removed from the room without changing the temperature, what will be the new pressure? The saturation vapour pressure at 25°C − 3.2 kPa.
Answer in brief:
What will happen to the mean square speed of the molecules of a gas if the temperature of the gas increases?
If the density of oxygen is 1.44 kg/m3 at a pressure of 105 N/m2, find the root mean square velocity of oxygen molecules.
Energy is emitted from a hole in an electric furnace at the rate of 20 W when the temperature of the furnace is 727°C. What is the area of the hole? (Take Stefan’s constant σ to be 5.7 × 10-8 Js-1 m-2K-4.)
The emissive power of a sphere of area 0.02 m2 is 0.5 kcal s-1m-2. What is the amount of heat radiated by the spherical surface in 20 seconds?
The number of degrees of freedom, for the vibrational motion of a polyatomic molecule, depends on the ______
Calculate the value of λmax for radiation from a body having a surface temperature of 3000 K. (b = 2.897 x 10-3 m K)
On what, the values of absorption coefficient, reflection coefficient, and transmission coefficient depend, in addition to the material of the object on which the radiation is an incident?
Above what temperature, all bodies radiate electromagnetic radiation?
A metal cube of length 4 cm radiates heat at the rate of 10 J/s. Find its emissive power at a given temperature.
Explain in detail the kinetic interpretation of temperature.
A ring of mass m and radius r rotates about an axis passing through its centre and perpendicular to its plane with angular velocity `omega`. Its kinetic energy is ______.
The average translational kinetic energy of a molecule in a gas is 'E1'. The kinetic energy of the electron (e) accelerated from rest through p.d. 'V' volt is 'E2'. The temperature at which E1 = E2 is possible, is ______.
Two molecules of a gas have speeds of 9 × 10 6 ms−1 and 1 × 106 ms−1, respectively. What is the root mean square speed of these molecules?
A gas mixture consists of molecules of types A, B and C with masses mA > mB > mC. Rank the three types of molecules in decreasing order of rms speeds.
An insulated container containing monoatomic gas of molar mass m is moving with a velocity vo. If the container is suddenly stopped, find the change in temperature.
Explain why there is no atmosphere on moon.
23Ne decays to 23Na by negative beta emission. Mass of 23Ne is 22.994465 amu mass of 23Na is 22.989768 amu. The maximum kinetic energy of emitted electrons neglecting the kinetic energy of recoiling product nucleus is ______ MeV.
Which of the following materials is diathermanous?
