Advertisements
Advertisements
प्रश्न
Estimate the average thermal energy of a helium atom at room temperature (27 °C).
Advertisements
उत्तर
At room temperature, T = 27°C = 300 K
Average thermal energy = `3/2` kT
Where k is Boltzmann constant = 1.38 × 10–23 m2 kg s–2 K–1
`therefore 3/2kT = 3/2 xx 1.38 xx 10^(-38) xx 300`
= 6.21 × 10–21J
Hence, the average thermal energy of a helium atom at room temperature (27°C) is 6.21 × 10–21 J.
APPEARS IN
संबंधित प्रश्न
Molar volume is the volume occupied by 1 mol of any (ideal) gas at standard temperature and pressure (STP: 1 atmospheric pressure, 0 °C). Show that it is 22.4 litres
An oxygen cylinder of volume 30 litres has an initial gauge pressure of 15 atm and a temperature of 27 °C. After some oxygen is withdrawn from the cylinder, the gauge pressure drops to 11 atm and its temperature drops to 17 °C. Estimate the mass of oxygen taken out of the cylinder (R = 8.31 J mol–1 K–1, molecular mass of O2 = 32 u)
Estimate the total number of air molecules (inclusive of oxygen, nitrogen, water vapour and other constituents) in a room of capacity 25.0 m3 at a temperature of 27 °C and 1 atm pressure
At what temperature is the root mean square speed of an atom in an argon gas cylinder equal to the rms speed of a helium gas atom at – 20 °C? (atomic mass of Ar = 39.9 u, of He = 4.0 u).
What do you understand by gas?
What is diffusion? Give an example to illustrate it.
Give reasons for the following:
Gas fills the vessel completely in which it is kept.
Match the following:
|
|
Column A |
Column B |
|
(a) |
cm3 |
(i) Pressure |
|
(b) |
Kelvin |
(ii) Temperature |
|
(c) |
Torr |
(iii) Volume |
|
(d) |
Boyle's law |
(iv) `"V"/"T" = ("V"_1)/("T"_1)` |
|
(a) |
Charles's law |
(v) `"PV"/"T" = ("P"_1 "V"_1)/"T"_1` |
|
|
|
(vi) PV = P1V1 |
Fill in the blanks:
If the temperature is reduced to half, ………….. would also reduce to half.
A gas occupies 500 cm3 at a normal temperature. At what temperature will the volume of the gas be reduced by 20% of its original volume, the pressure is constant?
Name or state the following:
The standard pressure of a gas in cm. of mercury corresponding to one atmospheric pressure.
Give reason for the following:
Temperature remaining constant the product of the vol. & the press, of a given mass of dry gas is a constant.
Estimate the average thermal energy of a helium atom at the temperature on the surface of the Sun (6000 K).
Which of the following diagrams (Figure) depicts ideal gas behaviour?
 (a) |
 (b) |
 (c) |
 (d) |
Calculate the number of atoms in 39.4 g gold. Molar mass of gold is 197g mole–1.
The volume V of an enclosure contains a mixture of three gases, 16 g of oxygen, 28 g of nitrogen and 44 g of carbon dioxide at absolute temperature T. Consider R as universal gas constant. The pressure of the mixture of gases is ______.
At room temperature, a diatomic gas is found to have an r.m.s. speed of 1930 ms-1. The gas is ______.
