bubble HCl gas into dioxane. Calculate the weight increased, then you can know the exact concentration of the HCl solution.

Preparing a 4M HCl solution in dioxane is not recommended in a standard chemistry lab due to significant safety risks. Both HCl and dioxane are hazardous, and their mixture can form explosive peroxides. Safer alternatives should be considered, such as using commercially available solutions or aqueous HCl, and the procedure should only be attempted in specialized facilities with proper safety equipment and trained personnel.

Both HCl and dioxane are hazardous; proper safety gear should be worn when preparing them in a chemistry lab. Then you can follow: M1V1=M2V2 formula to calculate the required volume of HCL in dioxane.