If you can not see a figure, please activate the Java Applet.    (Ver. 08.11.2006)    return to back      Japanese Version



Calculation method

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

    W = 100Ma/M,   M = Ma+Mb = VD,   C = 1000Ma/FV,   R = V/Mb,   1L = 1000mL

where Ma(g) is mass of NaCl, Mb(g or mL) mass or volume of water before dissolution, M(g), V(mL), D(g/mL), W(%), and C(mol/L) mass, volume, density, mass percentage, and molarity of solution after dissolution, R volume of solution after dissolution/volume of H2O before dissolution, F(g/mol) formula weight of NaCl.

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 H2O to concentration.

Preparation method

Wash and dry apparatus beforehand.

Normal preparation
1  Measure distilled water with a measuring cylinder.
2  Weigh NaCl with a balance, dissolve NaCl with the distilled water in a beaker.

Precision preparation
3  Weigh NaCl with a beaker and an electric balance.
4  Dissolve NaCl with distilled water, carefully transfer the solution to a volumetric flask.  Rinse the beaker with distilled water 2 or 3 times, transfer the washings to the flask.
5  Stir occasionally, add distilled water up to the mark line of the flask.
6  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

Carefully operate the balance.  Don't load over the maximum limit.  Clean when you spill chemicals.

Volume of measuring flask is fixed (for example, ·· , 100mL, 200mL, 250mL, 500mL, 1000mL, ··).  Correctly adjust the level of meniscus.