1. Determine the Formula of the Chloride Salt

Since we want a 1.0 M solution of sodium cations (Na+), the chloride salt we'll use is sodium chloride (NaCl).

2. Calculate the Molar Mass of NaCl

* Na: 22.99 g/mol

* Cl: 35.45 g/mol

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

3. Calculate the Moles of NaCl Needed

* Molarity (M) = moles of solute / liters of solution

* We want a 1.0 M solution and 100 mL (0.1 L) of solution.

* moles of NaCl = Molarity x volume = 1.0 M x 0.1 L = 0.1 moles

4. Calculate the Mass of NaCl Needed

* mass = moles x molar mass

* mass = 0.1 moles x 58.44 g/mol = 5.844 g

Therefore, you would need 5.844 grams of sodium chloride (NaCl) to make a 100 mL solution that is 1.0 M in sodium cation.