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Calculation method

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

    W = 100M_a/M,   M = M_a+M_b = VD,   M_b = V_bD_b,   C = 1000M_a/FV

    R = V/V_b,   1 L = 1000 mL

where M_a(g) is mass of potassium chloride before dissolution, M_b(g), V_b(mL), and D_b(g/mL) mass, volume, density of pure 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 pure water before dissolution, F(g/mol) formula weight of potassium chloride.

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 water to concentration.

Precise preparation method

Wash and dry apparatus beforehand.

1  Weigh potassium chloride with a weighing bottle (or a beaker) and an electric balance.
2  Dissolve potassium chloride with pure water, carefully transfer the solution to a volumetric flask.  Rinse the weighing bottle (or the beaker) with pure water 2 or 3 times, transfer the washings to the flask.
3  Stir occasionally, add pure water up to the mark line of the flask.
4  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

If potassium chloride solution comes into the mouth, immediately spit it out and rinse out the mouth with water.

If potassium chloride solution gets in contact with the eyes or spilled into the skin, immediately wash it with water.

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.