Answer: It is true that Your friend should release the 
first.
Explanation:
The velocity of particles of a gas is inversely proportional to the mass of gas. This means that more is the mass of gas less will be its velocity.
Or, more will be the mass of gas more slowly it will move from one place to another.
The molar mass of chlorine gas is more than the molar mass of hydrogen gas. Therefore, chlorine gas will move slowly.
So, your friend should release the gas first and then according to the length of room you should release the 
gas.
Thus, we can conclude that it is true that Your friend should release the first.
A.
H₃C-CH₃
this is called ethane
B.
H₃C-CH₂-CH₂-CH₃
this is called butane
C.H₃C-CH₂-CH₂-CH₂-CH₂-CH₃
this is called hexane
D.
H₃C-CH₂-CH₂-CH₂-CH₂-CH₂-CH₃
this is called heptane
It has different moleculs sorry I am guessing
To get moles. divide mass by molar mass.Molar mass of
Na is 23
and for Cl is 35.5.
the total molar mass of NaCl is 23+35.5 = 58.5mol/gUse the mass and divide by this number30.22g divide by 58.5mol/g and you will get 0.5166 mole.
Since the molecule has 1 Na to 1 Cl, and that the number of moles for NaCL is 0.5166. All of them would be 0.5166molesNa = 0.5166 x 1 = 0.5166molesCl = 0.5166 x 1 = 0.5166moles
to get number of atoms. Multiply your mole by Avogadro number which is 6.022x10^23Na = 0.5166 x 6.022E23 = 3.111x10^23Cl = 0.5166 x 6.022E23 = 3.111x10^23
