What is the mass of 6.53 X 10^23 atoms of Ag?

Answer 1

Hello, Klohe,

We can convert the number of atoms of any element, or compound, into moles using avogadro's number, 6.02x10²³.

1 mole of anything is 6.02x10²³ of whatever item is being described. The word mole, in this context, represents a unit of count of the number of silver atoms. One mole of Ag atoms would be 6.02x10²³ of those atoms. This number has a special value in science because it can be related to the mass of that number of atoms by that element's atomic weight, in atomic mass units (amu).

The atomic weight of silver is 107.87 amu. If one has 107.87 grams of silver two things will be true:

1. You will have more friends
2. You will have 1 mole, or 6.02x10²³ of silver atoms

It is the latter one that should get your attention. The atomic weight of any element, and of any compound, will have 6.02x10²³ atoms or molecules of that substance. This relationship provides an extemely useful conversion factor; the grams required of any substance to yield Avogadro's number of particles of that material. So each element (and compound) has it's own conversion factor.

Mass (amu) = 1 mole

Slver's atomic mass of 107.87 amu can be rewitten as: 107.87 grams Ag = 1 mole Ag

Rewriting this as a conversion factor: 1= (107.87 grams Ag/mole Ag). We say the molar mass of Ag is 10.87 grams/mole.

Now let's find out how many moles of silver are in the 6.53x10²³ atoms that were given to you (us).

(6.53x10²³ atoms Ag)/(6.02x10²³ atoms/mole) = 1.08 moles Ag

Then use the conversion factor:

(1.08 moles Ag)*(107.87 grams Ag/mole Ag) = 117 grams of Ag

Now you can look more closely at having more friends.

I hope this helps,

Bob