Adiatomic gas has the molar mass of 38.00g/mol. what is the possible formula?

The answer would be F₂. This is because you have 2 fluorine atoms. so you divide the 38g/mol by 2 atoms which gets you 19 g/mol per atom. Now all you have to do is find the atom with the molar mass of 19g/mol which is fluorine.

 I hope this helps :)

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%