Question

Which statement is true for a solution when its concentration of hydroxide ions becomes equal to the concentration of hydronium ions?
It becomes more acidic.

It becomes more alkaline.

Its pH becomes equal to 0.

Its pH becomes equal to 7.

Answer 1

Answer:

Option 4th, TRUE . Its pH becomes equal to 7.

Explanation:

[H₃O⁺] = [OH⁻]

pH = pOH → 7

[H₃O⁺] > [OH⁻]  → pH < 7 ⇒ acidic solution

[H₃O⁺] < [OH⁻]  → pH > 7 ⇒ basic solution

pH = 0 does not exist.

Answer 2

Answer : The correct statement is, Its pH becomes equal to 7.

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 becomes equal to the concentration of hydronium ions then its pH becomes equal to 7.

Hence, the correct statement is, Its pH becomes equal to 7.