Answer:
She should use 0.75 mol.
Explanation:
By definition, molarity (M) is the number of moles of solute per liter of solution. One liter of solution is equal to 1000 mL.
Therefore,
1000 mL -------- 1.5 moles of NaCl
500 mL --------- x= 0.75 moles of NaCl
The moles contained in 500 mL of a 1.5 M NaCl solution are 0.75.