Which one of the following statements is not true?

Options

A. the conjugate base of `H_(2)PO_(4)^(-)` is `HPO_(4)^(2-)`
B. `pH+pOH=14` for all aqueous solutions at `25^(@)C`.
C. The `pH` of `1xx10^(-8)M HCl` is `8`.
D. `96,500` coulombs of electrcity when passed through a `CuSO_(4)` solution deposities `1` gram equivalent of copper at the cathode.

Explanation

To determine which statement is not true, we will analyze each of the four statements provided in the question.

**Step 1: Analyze the first statement.**
- The statement claims that the conjugate base of H₂PO₄⁻ is HPO₄²⁻.
- To find the conjugate base, we need to remove one hydrogen ion (H⁺) from H₂PO₄⁻.
- When we remove H⁺ from H₂PO₄⁻, we get HPO₄²⁻.
- Therefore, this statement is **true**.

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