Answer:
[NaOH] = 1 M
Step-by-step explanation:
To determine molarity (mol/L) we:
Convert the mass of solute to moles
20 g . 1 mol / 40 g = 0.5 moles of NaOH
Convert the volume of solution from mL to L
500 mL . 1 L / 1000 mL = 0.5 L
Moles of solute / Volume of solution (L) → Molarity
0.5 mol / 0.5L = 1 M
This solution is 1 M, which means that 1 mol of solute (NaOH) is contained in 1L of solution.