1. Find the moles of NaCl

* The molar mass of NaCl is 58.44 g/mol (22.99 g/mol for Na + 35.45 g/mol for Cl)

* Moles of NaCl = (mass of NaCl) / (molar mass of NaCl)

* Moles of NaCl = 23.4 g / 58.44 g/mol = 0.400 mol

2. Calculate the Molarity

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

* Molarity = 0.400 mol / 10.0 L = 0.0400 M

Therefore, the molarity of the 10.0 L aqueous solution containing 23.4 grams of sodium chloride is 0.0400 M.