The pH value of solution is 2. If its pH value is to be doubled then the H+ ion concentration of the original solution has to be decreased by :

Options

A. two times
B. four times
C. fifty times
D. hundred times

Explanation

To solve the problem, we need to determine how much the concentration of H⁺ ions must decrease when the pH of a solution changes from 2 to 4. Let's break it down step by step.

### Step 1: Understand the relationship between pH and H⁺ concentration
The pH of a solution is defined as:
\[ \text{pH} = -\log[H^+] \]
where \([H^+]\) is the concentration of hydrogen ions in moles per liter.

### Step 2: Calculate the initial H⁺ concentration
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