What is the majority of 0.50 g of na dissolved in a 1.5 l solution

The correct answer is 0.014467 M.  

Molarity is defined as the number of moles present in a liter solution, that is, number of moles / liter solution.  

The molar mass of sodium (Na) is 23.0 g/mol

Thus, 1 mole of Na contains 23.0 g

Now, x moles of Na contains 0.50 g

Moles = 0.50 × 1 / 23.0

Moles = 0.50 / 23.0  

= 0.0217 moles of Na

Molarity = Number of moles / liters of solution

= 0.0217 / 1.5

= 0.014467 M