Question

A sodium atom has a mass of 22.99 u. Use Avogadro’s

constant and the conversion factor 1.661 3 10–24 g/u to

calculate the mass of 1.00 mol of sodium atoms.

Answer 1

1 atom Na = 22.99 u

1 u = 1.661*10^-24 g

1atom Na=22.99* 1.661*10^-24 =3.82*10^-23 g

According to Avogadro's law, 1 mole of a substance contains 6.02 * 10²³ particles (atoms, molecules).

$1~mol ~Na = ~6.02*~10^{23} * ~3.82*~10^{-23} =~\bold{23 ~g}$

Answer: 23 g