Use concentrated hydrochloric acid and distilled water
Check the acid concentration on the reagent label
For 1 N HCl, use the equivalent dilution based on the stock concentration
If using concentrated HCl at about 37% w/w, add about 83 mL of acid to distilled water and make up to 1 L total volume
Add acid to water slowly, never water to acid
Mix well
Allow the solution to cool if it warms during mixing
Transfer to a volumetric flask
Add distilled water up to the final 1 L mark
Mix thoroughly
Label the container as 1 N HCl
Store in a suitable acid-resistant container