What is the molarity of 15g of licl dissolved in 500ml of water?

Molarity is the concentration of a given solution in moles per liters. It defines the number of moles contained in 1 liter of a solution.
In this case, 1 mole of lithium chloride contains 42.4 g
Therefore, 15 g contain 15/42.4 moles =0.354 moles
0.354 moles are contained in 500 ml , thus 1 liter will have ,
 0.354 moles × 1000/ 500 = 0.707 moles
Thus, the molarity of LiCl = 0.707 M