1. Understand the Chemical Formula

Sodium chloride (NaCl) has a 1:1 ratio of sodium (Na+) ions to chloride (Cl-) ions. This means for every chloride ion, there's one sodium ion.

2. Calculate Moles of Chloride

* Find the molar mass of chloride (Cl): The molar mass of chlorine is 35.45 g/mol.

* Divide the mass of chloride by its molar mass:

25.75 g Cl / 35.45 g/mol Cl = 0.727 mol Cl

3. Calculate Moles of Sodium

* Use the mole ratio from the chemical formula: Since there's one sodium ion for every chloride ion, there are also 0.727 mol of sodium ions.

4. Calculate the Number of Sodium Ions

* Use Avogadro's number: 6.022 x 10^23 ions/mol

* Multiply the moles of sodium by Avogadro's number: 0.727 mol Na x 6.022 x 10^23 ions/mol = 4.38 x 10^23 sodium ions

Therefore, there are approximately 4.38 x 10^23 sodium ions in 25.75 grams of chloride.