Question

how to do preparation of hcl

Answer 1

Before we begin, you need to know what is Normality (N). Normality is used to measure the concentration of acid or base in the solution.Normality is similar to molarity as molarity measure the concentration of ions or compounds in a solution while normality represent the molar concentration of acid component or base component.

To know the normality, simply multiply the molarity with the number of hidrogen ions (H+) in the acid solution or hydroxide ions (OH-) in the base solution. 
(*HCL only has 1 hidrogen ion)

Now to dilute 0.1 M HCL from 37.5% concentrated HCL solution, you need to find the normality first. Simply multiply 0.1 M with 1 will give you 0.1 N.

The equivalent mass is the molar mass divided by by the number of hydrogen ions. 
Molar mass for HCL is 36.4611 g/mol. Since HCL only has one hydrogen ion, the equivalent mass will be 36.4611. The volume will be in 1 litre. HCL specific gravity is 1.189.

Insert the details in the formula,

Grams of compound needed = (0.1 N)(36.4611)(1 Litre) = 3.6461

Volume of concentrated acid needed = (3.6461)/(0.375 x 1.189) = 8.1774 ml

So, 8.1774 ml of 37.5% concentrated HCL is needed to prepare 0.1 M HCL.

I hope this will help you.