Answer:
3.25 M
Step-by-step explanation:
Number of moles = mass/ molar mass
mass of NaOH = 65 g
Molar mass of NaOH = 40 g/mol
Number of moles of NaOH = 65g/40 g/mol = 1.625 moles
Let us recall that;
n = CV
n = number of moles of solute
C = concentration of solution
V = volume of solution
C = n/V
n = 1.625 moles
V = 500/1000 L = 0.5 L
C = 1.625 moles/0.5
C = 3.25 M