What will be the pOH of a solution formed by mixing 40 cm 3 of 0.1 M HCl with 10 cm 3 of 0.45 M NaOH at 25°C.

Question

TestHub · Accepted Answer

Number of moles of HCl is calculated as:

$\frac{MV}{1000} = \frac{0.1 \times 40}{1000} = 0.004$

Number of moles of NaOH is calculated as:

$\frac{MV}{1000} = \frac{0.45 \times 10}{1000} = 0.0045$

Remaining moles of NaOH after neutralization:

$0.0045 - 0.004 = 0.0005$

Molarity of OH⁻ is:

$\frac{0.0005}{50} \times 1000 = 0.01 M$

Therefore, pOH is:

$- lo g_{10} (0.01) = 2$

And pH is:

$14 - pO H = 14 - 2 = 12$

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