How to prepare 0.5m solution of HCL
From what? Stock solution?
Example> assume your stock solution is 12M.
so you want to dilute it 12/.5=24 times. That means, one part stock + 23 parts water.
Say you want to make 3 liters of the .5 solution. Then one part=3liters/24=you do it.
so add one part (3/24 liters) stock to 23parts or 3/24*23 liters), stir, and label. ALWAYS ADD ACID TO WATER>