Question

What is the mass of 8.30x1024 molecules of NH3?

Answer 1

The molar mass of NH₃ is 17.03 g/mol

1 mole of anything contains Avogadro's number of particles (6.022 x 10²³). Therefore,

$m(NH_3)=8.30\times10^{24}molecules\times\frac{1mol(NH_3)}{6.022\times10^{23}molecules(NH_3)}\times\frac{17.03g(NH_3)}{1mol(NH_3)}=235g$

Answer: 235 g