Question

1. How many moles of Cl are there in a sample that contains 6.20x1022 chlorine atoms? moles 2. How many chlorine atoms are there in a sample that contains 2.66 mol of Cl? atoms

Answer 1

1)
use:
number of mol = number of atoms / Avogadro’s number
number of mol = 6.2*10^22 / 6.022*10^23 mol
number of mol = 0.103 mol
Answer: 0.103 mol

2)
use:
number of atoms = number of moles * Avogadro’s number
= 2.66 * 6.022*10^23 atoms
= 1.602*10^24 atoms
Answer: 1.60*10^24 atoms