Question

formula of molecular mass​

Answer 1

n = mass in g / molar mass

molar mass = mass in g / n

If you know the constituent elements, and the molecular formula you have to multiply atomic mass of each constituent by the number of times they occur in one molecule of the compound.

e.g. HCOOH

Hydrogen occurs two times and its atomic mass is 1 hence it contributes 2∗1=2 to the molecular mass

Carbon occurs once and has an atomic mass of 12. So it contributes 12∗1=12

Oxygen occurs twice and has an atomic mass of 16 so it contributes 16∗2=32

So you get a total of 2+12+32=46amu

Or if you know the mass of said number of moles(n), you take the the mass and divide it by n/

5 moles of HCOOH weigh 230 grams. So molecular mass = 230/5=46 amu