Question

If each of these represents a concentration of [H3O+]
, which one is most alkaline?(1 point)
Responses

1 x 10−3
1 x 10−3

1 x 10−5
1 x 10−5

1 x 10−8
1 x 10−8

1 x 10−13

Answer 1

To determine which of the given concentrations of \([H_3O^+]\) is most alkaline, we need to understand that pH is a measure of hydrogen ion concentration:

\[
\text{pH} = -\log[H_3O^+]
\]

Lower concentrations of \([H_3O^+]\) correspond to higher pH values, indicating more alkaline (basic) solutions.

Here are the given concentrations and their corresponding pH values:

1. \( [H_3O^+] = 1 \times 10^{-3} \, \text{M} \)
\(\text{pH} = -\log(1 \times 10^{-3}) = 3\)

2. \( [H_3O^+] = 1 \times 10^{-5} \, \text{M} \)
\(\text{pH} = -\log(1 \times 10^{-5}) = 5\)

3. \( [H_3O^+] = 1 \times 10^{-8} \, \text{M} \)
\(\text{pH} = -\log(1 \times 10^{-8}) = 8\)

4. \( [H_3O^+] = 1 \times 10^{-13} \, \text{M} \)
\(\text{pH} = -\log(1 \times 10^{-13}) = 13\)

From these calculations, we see that the overall trend shows higher pH values associated with lower concentrations of \([H_3O^+]\).

Thus, the most alkaline solution corresponds to:

**\(1 \times 10^{-13} \, \text{M} \) \( [H_3O^+] \), which has a pH of 13.**