Question

[PLEASE ANSWER ASAP, ON TIME LIMIT!] The pH level of a substance can be determined by the formula pH = –log[H+], where [H+] is the hydrogen ion concentration in moles per liter. An alkaline substance has a pH level between 7 and 14. Which ion concentration corresponds to an alkaline substance?

Answer choices in picture.

Answer 1

B

Explanation:

Edg2020

Answer 2

Option (2)

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 ×
`10^(-a)`

Here 'a' is between 7 and 14.

Which means an alkaline substance must have the concentration between
`1* 10^(-7)` to
`1* 10^(-14)`.

From the given options,
`5* 10^(-12)` moles per liter lies in the given range.

Therefore, Option (2) will be the answer.