How do you find formula mass of a compound?

1 Answer
Mar 24, 2018

Answer:

Got a Periodic Table....?

Explanation:

Of course you have, you are doing your chemistry homework...

So let us find the formula mass of #CaSO_4#..

The Table tells us that the molar masses of calcium, sulfur, and oxygen, are #40.1*g*mol^-1#, #32.06*g*mol^-1#, and #16.0*g*mol^-1#, respectively. The mole is simply a large number so chosen that #1*mol# of #""^1H# ATOMS, has a mass of #1*g# precisely... Of course, the elemental molar masses are listed on the Periodic Table; you are not required to remember then, tho you will soon commit the masses of the common atoms to memory..

And so we take the sum...

#"Formula mass of calcium sulfate"-={40.10+32.06+4xx16.00}*g*mol^-1=136.16*g*mol^-1#...