`2.5mL`of `2//5M` weak mono-acidic base `(K_(b) = 1 xx 10^(-12)` at `25^(@)C)` is titrated with `2//15M HCI` in water at `25^(@)C`. Find the concentration of `H^(o+)` ions at equivalence point. `(K_(w) = 1 xx 10^(-14)at 25^(@)C)`
a. `3.7 xx 10^(-13)M` b. `3.2 xx 10^(-7)M`
c. `3.2 xx 10^(-2)M` d. `2.7 xx 10^(-2)M`

Explanation

To solve the problem step by step, we will follow these steps:

### Step 1: Calculate the moles of the weak base (BOH)
Given:
- Volume of the weak base (BOH) = 2.5 mL = 0.0025 L
- Molarity of BOH = \( \frac{2}{5} \, M = 0.4 \, M \)

Using the formula for moles:
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