Related to chemistry – 231.

Physical chemistry–A-2.

ज्ञानसागरटाइम्स1 hour agoLast Updated: May 5, 2026

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One gm –mole of Heat S.T.P. = 22.4 lit
Case 2:- molar volume at R.T.P = 24.45 lit
One gm-mole oxygen at R.T.P = 22.45 lit
One gm-atom of Heat R.T.P =22.45 lit
Unit of volume
M3 ,dm3, cm3
1m = 10dm = 100cm
1m3 =1000m3 ( lit ) = 106cm3(cc)
1m3 = 1000lit
1lit = 1000cc = 1000ml
Density:-
Mass per unit volume is called density
Density = mass/volume =
Unit = gm/cc, gm/lit, kg /m3
D = 1010kg /m3 =1010x1000gm/1000lit
= 1010gm / it =1010gm/1000cc = 1.010gm/cc
Density of H2o d = 1gm / cc
Question:- calculate the total no of atoms in 11.2 lit f oxygen of oxygen at STP
Solution:-
One gm-mole oxygen = 32gm
= 22.4lit = 3.011x1023mlecular
11.2 lit = 3.011×1023
1molecular = 2atom
= 3.011×1023 x2
= 6.022×1023
Measurable properties of gas·
( 1) Mass
Unit = gm, kg , mole
(2) volume
Volume of gas = volume of vessel
M =VX d

Unit of volume = m3,dm3(lit) cm3(cc)
(3) pressure = force/area
Unit of pressure
1atom pressure = 76m of Hg
= 760mm of Hg
= 1.01×105 N / m2(or) pa
= 1.01×106 dyne /cm2
= 760 bar
= 1.013 bar
(4) Temperature
Unit = 00c and Kelvin
k = t0c+273
PV = NRT
P = pressure in atom units
V = volume in lit
N = mole of gas
T = temperature in Kelvin
R = molar gas constant
= 0.0821 lit – atm/mole /k
PV = W/M RT
W = wt of gas in gm
M = M.W of gas
Relation between mass and mole·
No f mole = mass given in gm /formula wt
No of gm-atom = mass given in gm /AT Wt
No of gm-mole = mass given in gm /M.W
No of gm-ion = mass given in gm /ionic wt
Relation between volume and mole·
No of mole = volume in lit at S.T.P / 22.4
= volume in lit at R.T.P / 24.4m
The relation between number and mole