A. preparation of solutions in the acid range,pH 2 to pH 6
obtain 100 mL of boiled, distilled water . fill the first test tube about two-thirds full with standard 0.01 M solution of hydrochlorid acid, HCl,from the reagent shelf. since HCl is essentially 100% dissociated into ions in dilute solution, the H+ ion concentration of the solution is 1*10-2 mole/L and the pH is 2. prepare the other solutions of pH 3,pH 4, pH 5 and pH 6 by progressive tenfold dilutions starting with the solution pH 2. to prepare the pH 3 solution use a graduated cylinder to measure 1 mL of the pH 2 solution and 3 mL of the boiled distilled waTER for a total volume of 10 mL . stir carefully . remember pH 2 means 10-2 moles per liter H+ ion concentration and pH 3 is 10-3 moles/L,so any tenfold dilution changes the pH by one unit ( one exponent)
after filling the second test tube about two-thirds full , take 1 mL of the pH 3 solution and add 9 mL of boiled distilled water to make the pH 4 solution . take 1 mL of the pH 4 solution and add 9 mL of the boiled water to make the pH 5 solution . similarly prepare the pH 6 solution by diluting the pH 5 solution tenfold.
A. preparation of solutions in the acid range,pH 2 to pH 6obtain 100 mL of boiled, distilled water . fill the first test tube about two-thirds full with standard 0.01 M solution of hydrochlorid acid, HCl,from the reagent shelf. since HCl is essentially 100% dissociated into ions in dilute solution, the H+ ion concentration of the solution is 1*10-2 mole/L and the pH is 2. prepare the other solutions of pH 3,pH 4, pH 5 and pH 6 by progressive tenfold dilutions starting with the solution pH 2. to prepare the pH 3 solution use a graduated cylinder to measure 1 mL of the pH 2 solution and 3 mL of the boiled distilled waTER for a total volume of 10 mL . stir carefully . remember pH 2 means 10-2 moles per liter H+ ion concentration and pH 3 is 10-3 moles/L,so any tenfold dilution changes the pH by one unit ( one exponent) after filling the second test tube about two-thirds full , take 1 mL of the pH 3 solution and add 9 mL of boiled distilled water to make the pH 4 solution . take 1 mL of the pH 4 solution and add 9 mL of the boiled water to make the pH 5 solution . similarly prepare the pH 6 solution by diluting the pH 5 solution tenfold.
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