Here's how to calculate the number of moles in 20.67 g of sodium chloride (NaCl):

1. Find the molar mass of NaCl:

* Sodium (Na) has a molar mass of 22.99 g/mol

* Chlorine (Cl) has a molar mass of 35.45 g/mol

* Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol

2. Use the formula:

* Moles = Mass / Molar Mass

3. Substitute the values:

* Moles = 20.67 g / 58.44 g/mol

* Moles ≈ 0.354 mol

Therefore, there are approximately 0.354 moles of sodium chloride in 20.67 grams.