If one has 4.50 xx 10^224.50×1022 atoms of silver, what mass is available?
1 Answer
"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=6.0221413×1023mol−1 is Avogadro's number andMM 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
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
0.0747 cancel"mols unknown element" xx ("107.8682 g Ag")/(cancel"1 mol Ag")
= color(blue)("8.06 g Ag")