Find the number o

Given

Volume of ideal gas V=1cm³

1cm=m

V=m³

Temperature of ideal gas=0

T(K)=T ()+273.15

T=T(K)=0+273.15=273.15K

Pressure of ideal gas P=mm of Hg

1mm of Hg= 133.32Pa

P=mm of Hg=133.32Pa

We know ideal gas equation

PV=nRT

Where V= volume of gas

R=gas constant=8.31J/molK

T=temperature

n=number of moles of gas

P=pressure of gas.

So,

Number of molecules = Avogadro numbernumber of moles

Number of molecules=n

=

=3.538

Therefore,

Number of molecules in 1 cm³ of an ideal gas at 0°C and at a pressure of 10^–5 mm of mercury is 3.538.