मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता १२ वी

Calculate the average molecular kinetic energy (i) per kmol (ii) per kg (iii) per molecule of oxygen at 127°C, given that the molecular weight of oxygen is 32, R is 8.31 J mol−1K−1 and Avogadro’s

Advertisements
Advertisements

प्रश्न

Calculate the average molecular kinetic energy 

  1. per kmol 
  2. per kg 
  3. per molecule 

of oxygen at 127°C, given that the molecular weight of oxygen is 32, R is 8.31 J mol−1K1 and Avogadro’s number NA is 6.02 × 1023 molecules mol1.

संख्यात्मक
Advertisements

उत्तर

Data: T = 273 + 127 = 400 K,

molecular weight = 32

∴ molar mass = 32 kg/kmol,

R = 8.31 Jmol-1K-1,

NA = 6.02 × 1023 molecules mol-1

(i) The average molecular kinetic energy per kmol of oxygen = the average kinetic energy per mol of oxygen × 1000

`= 3/2 "RT" xx 1000`

= `3/2(8.31)(400)(10^3)"J"/"kmol"`

= (600)(8.31)(103)

= 4.986 × 106 J/kmol

(ii) The average molecular kinetic energy per kg of oxygen

= `3/2 "RT"/"M"_0`

= `(4.986xx10^6  "J"//"mol")/(32  "kg"//"kmol")`

= 1.558 × 105 J/kg.

(iii) The average molecular kinetic energy per molecule of oxygen

= `3/2 "RT"/"N"_"A"`

= `(4.986 xx 10^6  "J"//"mol")/(6.02 xx 10^23  "molecule"//"mol")`

= 8.282 × 10-21 J/molecule

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Kinetic Theory of Gases and Radiation - Exercises [पृष्ठ ७४]

APPEARS IN

बालभारती Physics [English] Standard 12 Maharashtra State Board
पाठ 3 Kinetic Theory of Gases and Radiation
Exercises | Q 18 | पृष्ठ ७४

संबंधित प्रश्‍न

When we place a gas cylinder on a van and the van moves, does the kinetic energy of the molecules increase? Does the temperature increase?


A gas is kept in an enclosure. The pressure of the gas is reduced by pumping out some gas. Will the temperature of the gas decrease by Charles's low?


Is it possible to boil water at room temperature, say 30°C? If we touch a flask containing water boiling at this temperature, will it be hot?


The pressure of an ideal gas is written as \[P = \frac{2E}{3V}\] . Here E refers to 

 

The mean square speed of the molecules of a gas at absolute temperature T is proportional to 


During an experiment, an ideal gas is found to obey an additional law pV2 = constant. The gas is initially at a temperature T and volume V. Find the temperature when it expands to a volume 2V.

Use R = 8.3 J K-1 mol-1


Figure shows two vessels A and B with rigid walls containing ideal gases. The pressure, temperature and the volume are pA, TA, V in the vessel A and pB, TB, V in the vessel B. The vessels are now connected through a small tube. Show that the pressure p and the temperature T satisfy `Ρ/T = 1/2 ({P_A}/{T_A}+{P_B}/{T_B))` when equilibrium is achieved.


The weather report reads, "Temperature 20°C : Relative humidity 100%". What is the dew point?


The temperature and the dew point in an open room are 20°C and 10°C. If the room temperature drops to 15°C, what will be the new dew point?


Using figure, find the boiling point of methyl alcohol at 1 atm (760 mm of mercury) and at 0.5 atm.


A glass contains some water at room temperature 20°C. Refrigerated water is added to it slowly. when the temperature of the glass reaches 10°C, small droplets condense on the outer surface. Calculate the relative humidity in the room. The boiling point of water at a pressure of 17.5 mm of mercury is 20°C and at 8.9 mm of mercury it is 10°C.


An adiabatic cylindrical tube of cross-sectional area 1 cm2 is closed at one end and fitted with a piston at the other end. The tube contains 0.03 g of an ideal gas. At 1 atm pressure and at the temperature of the surrounding, the length of the gas column is 40 cm. The piston is suddenly pulled out to double the length of the column. The pressure of the gas falls to 0.355 atm. Find the speed of sound in the gas at atmospheric temperature.


Answer in brief:

A gas in a cylinder is at pressure P. If the masses of all the molecules are made one-third of their original value and their speeds are doubled, then find the resultant pressure.


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.


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?


Find the temperature of a blackbody if its spectrum has a peak at (a) λmax = 700 nm (visible), (b) λmax = 3 cm (microwave region) (c) λmax = 3 m (short radio waves). (Take Wien’s constant b = 2.897 × 10-3 m.K).


Why the temperature of all bodies remains constant at room temperature?


Compare the rate of radiation of metal bodies at 727 °C and 227 °C.  


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 ______.


Average kinetic energy of H2 molecule at 300K is 'E'. At the same temperature, average kinetic energy of O2 molecule will be ______.


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 ______.


An ideal gas in a container of volume 500 cc is at a pressure of 2 × 105 N/m2. The average kinetic energy of each molecule is 6 × 10−21 J. The number of gas molecules in the container is ______. 


The molecules of a given mass of a gas have root mean square speeds of 100 ms−1 at 27°C and 1.00 atmospheric pressure. What will be the root mean square speeds of the molecules of the gas at 127°C and 2.0 atmospheric pressure?


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.


The Q-value of a nuclear reaction and kinetic energy of the projectile particle, KP are related as ______.


A proton, a deuteron and an α-particle with same kinetic energy enter into a uniform magnetic field at right angle to magnetic field. The ratio of the radii of their respective circular paths is ______.


Which of the following materials is diathermanous?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×