Answer:
Option (2)
Step-by-step explanation:
pH level of a substance is determined by the formula,
pH = - log[H+}
where [H+] is the hydrogen ion concentration
Let the [H+] ion concentration = a
a = -log[H+]
log[H+] = -a
[H+] = 1 × [tex]10^{-a}[/tex]
Here 'a' is between 7 and 14.
Which means an alkaline substance must have the concentration between [tex]1\times 10^{-7}[/tex] to [tex]1\times 10^{-14}[/tex].
From the given options, [tex]5\times 10^{-12}[/tex] moles per liter lies in the given range.
Therefore, Option (2) will be the answer.
