1. Find the molar mass of NaCl:
* Sodium (Na): 22.99 g/mol
* Chlorine (Cl): 35.45 g/mol
* Molar mass of NaCl: 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl:
* Moles = mass / molar mass
* Moles = 7.5 g / 58.44 g/mol
* Moles ≈ 0.128 mol
3. Calculate the number of formula units (NaCl units):
* One mole of any substance contains Avogadro's number of particles (6.022 x 10^23).
* Formula units of NaCl = 0.128 mol * (6.022 x 10^23 formula units/mol)
* Formula units of NaCl ≈ 7.71 x 10^22
4. Calculate the total number of atoms:
* Each formula unit of NaCl contains 1 sodium atom and 1 chlorine atom, for a total of 2 atoms.
* Total atoms = 7.71 x 10^22 formula units * 2 atoms/formula unit
* Total atoms ≈ 1.54 x 10^23 atoms
Therefore, there are approximately 1.54 x 10^23 atoms in 7.5 g of sodium chloride.
