If one has 4.50 xx 10^224.50×1022 atoms of silver, what mass is available?

1 Answer
Aug 2, 2017

"8.06 g Ag"8.06 g Ag,

i.e. the mass of a handful of silver.


This is easiest in steps:

"atoms" stackrel(N_A" ")(->) "mols" stackrel(M" ")(->) "mass"atomsNA molsM mass

where N_A = 6.0221413 xx 10^(23) "mol"^(-1)NA=6.0221413×1023mol1 is Avogadro's number and MM is the molar mass in "g/mol"g/mol of the thing we are looking at.

So, to get to mols, we utilize the number of whatchamacallits in "1 mol"1 mol:

4.50 xx 10^(22) cancel"atoms" xx ("1 mol")/(6.0221413 xx 10^(23) cancel"whatevers")

= "0.0747 mols of any atom"

To be specific to silver, we then need to use its molar mass M to identify the atom as silver. Look up the molar mass on a periodic table to find M = "107.8682 g/mol". Thus:

0.0747 cancel"mols unknown element" xx ("107.8682 g Ag")/(cancel"1 mol Ag")

= color(blue)("8.06 g Ag")