Calculate the number of atoms present in 5.6 litres of a (i) monoatomic, and (ii) diatomic gas at NTP.

Explanation

No. of moles of the gas at NTP = `5.6/(22.4) = 1/4`
`therefore` no. Of molecules of the gas `=1/4 xx 6.022 xx 10^(23)`
`=1.5 xx 10^(23)`
no. of molecules of the gas `=1/4 xx 6.022 xx 10^(23)`
`=1.5 xx 10^(23)`
Now, if the gas is monoatomic, the no. of atoms of the gas = no. of molecules `=1.5 xx 10^(23)`
And if the gas is diatomic,
no. of atoms `=2 xx` no. of molecules `=2 xx 1.5 xx 10^(23)`
`=3.0 xx 10^(23)`