تحضير محلول هيدروكسيد الصوديوم تركيز 3 مولارية أو 3 عيارية

2 thoughts on “تحضير محلول هيدروكسيد الصوديوم تركيز 3 مولارية أو 3 عيارية”

2. هل هذه التجربة حقيقية .
   ما هي قيمة درجة الحموضة PH في هذه الحالة
   اليست خارج المجال
   الا يجب أن يكون مجل pH من 1 ألى 14
   ارجو الرد

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   1. The pH of 3 M NaOH is 14.47, how can the calculate pH correct (14.47) if the maximum pH is 14?

      Turns out the equation people are using to calculate pH here is not exactly correct. The actual equation is

      pH = -log a(H+) => 14 + log a(OH-)

      where a(H+) refers to the activity of H+ and a(OH-) the activity of OH-. Activity refers to how a species ‘behaves’ vs what it’s concentration is. Activity is defined by:

      a(X) = f(X) * C

      This equation relates the concentration (C(X)) and activity (a(X)) via the function f(X). At low concentrations of X (e.g., H+ or OH-) the activity of a species and the concentration are nearly the same. However, at very high concentrations, activity declines relative to concentration. In the present case a 3 M NaOH solution is going to have a pH of 14 or slightly less.

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