Question

The concentration of hydroxide ions is less than the concentration of hydronium ions for acidic solutions. True False

Answer 1

Answer : The given statement is true.

Explanation :

pH : It is defined as the negative logarithm of hydrogen ion or hydronium ion concentration.

Mathematically,

$pH=-\log [H^+]$

• When the pH less than 7 then the solution is acidic and the concentration of hydrogen ion is greater than hydroxide ion.
• When the pH more than 7 then the solution is basic and the concentration of hydrogen ion is less than hydroxide ion.
• When the pH is equal to 7 then the solution is neutral and the concentration of hydrogen ion is equal to the hydroxide ion.

As per question, the concentration of hydroxide ions is less than the concentration of hydronium ions then its pH become less than 7 and the solution will be acidic.

Hence, the given statement is true.

Answer 2

Answer:

True

Explanation:

It's true because the pH is a measure of how basic or acid a solution is. In an acidic medium, the pH scales goes from 0 to 7. While in a basic medium goes from 7 to 14. The lower the pH value of the most acid the solution is.

1. The expression pH = -log(molar concentration of hydronium) allow to calculate the pH of a solution.

2. On the other hand, the expression pOH = -log(molar concentration of hydroxide) allow to determine the pOH of a solution.

The values of pH and pOH always obey the following expression:

pH + pOH = 14

Thus if for instance the pH becomes smaller the pOH must become bigger in order to fulfill the equation. Which means that the concentration of hydronium ions is greater than the hydroxide concentration.

For example, in an acidic medium:

if pH= 3, pOH= 11

In this case the molar concentration of hydronium is 0,001M. And the molar concentration of hydroxide ions is just 0,00000000001M.