units of universal gas constant-

universal gas constant

 

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    units of universal gas constant-

1. Value of  R in M.K.S. System

According to Avogadro’s law, the volume of one mole of a gas at NTP is 22.4 litre. Standard temperature & pressure at N.T.P. are 0⁰C & one atmosphere

P=1 atm.

V=22.4 l

n= 1 mole.

T=  273⁰K

R=0.0821 litre atmosphere/degree/mole.

 

2. Value of R. in C.G.S. System

If P is expressed in dyne/Cm² & V in Cm³

P=1 atm = 76 cm. of Hg = 76×13.6×981 dyne/cm²

V= 22.4 litre = 22400 ml = 22400 cm³

n= 1 mole

T= 0+273 = 273⁰K

= 8.3 ×10⁷ erg/degree/mole

= 8.3 Joule/degree/mole

Because one calorie is equivalent to 4.08×10⁷ erg. So

R =[ 8.3×10⁷ erg/degree/mole ×  1calorie] /( 4.08×10⁷ erg )

= 2 calorie/degree/mole