On the basis of the postulates of kinetic theory of gases, it is possible to derive the mathematical expression, commonly known as kinetic gas equation. `PV = 1/3 m n u^3?`
  where, P= Pressure of the gas, V a volume of the gas, m=Mass of a molecule, n = Number of molecules present in the given amount of a gas and u = root mean square speed
For one mole of gas, PV = RT and `n=N_A`
`1/3 m N_a u^2 = RT or 2/3 .1/2m N_A u^2 = N_A`
`[1/2mN_Au^2 = KE "per mole"] ,2/3K.E. = RT implies K.E. 3/2RT`
Average kinetic energy per mol does not depend on the nature of the gas but depends only on temperature. This, when two gases are mixed at the same temperature, there will be no rise or decrease in temperature unless both react chemically. 
Average kinetic energy per molecule = `("Average K.E. per mole")/N = 3/2(RT)/(N) implies 3/2kT` 
 where k is the Boltzmann constant 
 In deriving the kinetic gas equation, the use of the root mean square speed of the molecules is done, hecause it is 

Options

A. average speed of the molecules
B. the most probable speed of the molecules
C. root of average speed of the molecules
D. The most accurate form of speed

Answer

D

Explanation

Average velocity in vector.