Question

Find the pH of $0.005M$ $Ba{\left(OH\right)}_2$ solution at ${25}^{o}C$. Also calculate the pH value of the solution when $100ml$ of the above solution is diluted to $1000ml$. (Assume complete ionization of barium hydroxide)

• A. $8,9$
• B. $2.3$
• C. $10,12$
• D. $12,11$

Answer 1

Answer: (D)

$12,11$

concentration of $O{H}^{-}$ in the solution = $0.005\times 2=0.01mole/l$

$pOH=-log\left[0.01\right]=2$

$pH=14-pOH=14-2=12$

When 100 ml of this solution diluted to 1000 ml

Moles of $O{H}^{-}=0.01mole$

Concentration of $O{H}^{-}=\frac{0.01\times 100}{1000}=0.001$

$pOH=-log\left[{10}^{-3}\right]=3$

$pH=14-3=11$