Answer:
B. 5.0 × 10⁻¹² moles per liter.
Step-by-step explanation:
In this exercise we have to calculate the pH levels associated with respective hydrogen ion concentration based on the following formula:
[tex]pH=-\log [H^{+}][/tex]
Where [tex][H^{+}][/tex] is the hydrogen ion concentration, measured in moles per liter.
a) 3.5 × 10⁻¹⁶ moles per liter:
[tex]pH=-\log [3.5\times 10^{-16}][/tex]
[tex]pH \approx 15.456[/tex]
The substance is above the upper bound for alkaline substances.
b) 5.0 × 10⁻¹² moles per liter:
[tex]pH=-\log [5.0\times 10^{-12}][/tex]
[tex]pH \approx 11.301[/tex]
The substance is alkaline.
c) 1.0 × 10⁻⁷ moles per liter:
[tex]pH=-\log [1.0\times 10^{-7}][/tex]
[tex]pH= 7[/tex]
The substance is not acid nor alkaline.
d) 1.1 × 10⁻⁴ moles per liter:
[tex]pH=-\log [1.1\times 10^{-4}][/tex]
[tex]pH \approx 3.959[/tex]
The substance is acid.
Thus, we concluded that correct answer is B.
