Question

are the following solutions acidic, basic, ot neutral.

1. [H3O+] = 2.5 x 10-9 M

2. [OH-] = 1.6 x 10 -2 M

3. [H3O+] = 7.9 x 10-3 M

Answer 1

Answer:

1) Basic

2) Basic

3) Acidic

Explanation:

pH of a solution is a measure of the H3O+ ions in the solution and hence reflects its acidity.

$pH = -log[H3O+]$

Solutions are classified as acidic, basic or neutral based on the pH range

-pH < 7, acidic

- pH = 7, neutral

- pH > 7, basic

1) [H3O+] = 2.5*10^-9M

$pH = -log[H3O+]=-log[2.5*10^{-9}]=8.60$

Since pH > 7, solution is basic

2)[OH-] = 1.6*10^-2M

$pOH = -log[OH-]=-log[1.6*10^{-2}]=1.80$

pH = 14 - pOH = 14 - 1.80 =12.2

Since pH > 7, solution is basic

3) [H3O+] = 7.9*10^-3M

$pH = -log[H3O+]=-log[7.9*10^{-3}]=2.10$

Since pH < 7, solution is acidic