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Calculation method

The following relations exist among mass and volume of solution, etc.

    M_a = V_aD_cW_c/100,   M_b = V_b+V_aD_c(100-W_c)/100,   W = 100M_a/M,

    M = M_a+M_b = V_aD_c+V_b = VD,   C = 1000M_a/FV,   Q = V/V_b,   1L = 1000mL

where V_a(mL), W_c(%) and D_c(g/mL) are volume, mass percentage and density of conc. HCl aqueous solution before dilution, M_a(g) mass of dissolved HCl gas, V_b(mL) volume of diluent water before dilution, M_b(g) mass of total water, M(g), V(mL), W(%), C(mol/L), and D(g/mL) mass, volume, mass percentage, molarity, and density of solution after dilution, Q volume of solution after dilution/volume of diluent water before dilution, F(g/mol) formula weight of HCl.

An unknown value can be calculated with the use of relations shown above and known values.

You may use the upper table to convert concentration to density, volume of solution/volume of diluent water to concentration.

Preparetion method

Wash and dry apparatus beforehand.
1  Measure disstilled water with a measuring cylinder, and transfer the water to a beaker.
2  Measure conc. HCl aqueous solution with another measuring cylinder, and add slowly into the beaker with stirring.
3  If you need, transfer the solution to a reagent bottle and attach label showing the reagent's name, concentration, date, the person who prepared.

Caution

Hydrogen chloride gas evaporates from conc. hydrochloric acid aqueous solution to the space (air) avobe the solution in a bottle.  So, the bottle of conc. hydrochloric acid is filled with HCl gas.  When you open the cover spray appears.  Be careful for neither gas nor mist to get in contact with the eyes.  Moreover, there is toxicity in the gas and it has a pungent smell.  Deal with it in a well ventilated place so that gas may not be inhaled.

If conc. hydrochloric acid gets in contact with the eyes or is stained with the skin, immediately wash it with water.

Keep in mind that it generates heat when diluting conc. hydrochloric acid with water.  In adjusting the total volume of solution, do it after getting cold.

The presumed concentration of reagent grade chemicals is near saturation (about 37%).  When the exact concentration of dilute hydrochloric acid solution is required, titrate it against a solution of a base of known concentration, a standard solution; then, you can determine its exact concentration.