Answer:
3.63 x 10²³molecules
Explanation:
Given parameters:
Mass of methane = 9.65g
Unknown:
Number of molecules  = ?
Solution:
To solve this problem first, we find the number of moles of the given compound or molecule first.
The given molecule is methane;
  CH₄;
   Number of moles  = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of CHâ‚„ Â = 12 + 4(1) Â = 16g/mol
  Number of moles  = [tex]\frac{9.65}{16}[/tex]  = 0.603moles
So;
From mole concept;
   1 mole of a substance contains 6.02 x 10²³ molecules
  0.603moles of methane will contain 0.603  x  6.02 x 10²³
                                = 3.63 x 10²³molecules
