XeF6

formula mass =

molar mass =

Xenon hexafluoride's molar mass is about 245.28 g/mol
Formula mass is about 245.28 u.

Explanation:

So we want to find the formula mass of the XeF6 and there is a special formula for that.

You have to multiply the number of each element in XeF6 by the element's atomic mass.

The atomic mass of Xe is 131.293, and F's atomic mass is multiplied by 6, due to the 6 at the bottom. F's atomic mass is 18.998403, so we multiply the atomic number by 6, which would equal 113.990418. Round if you want, but it would equal mostly the same thing. Add it up to get ≈245.28, which is the same thing.

Therefore the formula mass of XeF6 is 245.28 u.