If molarity of NaOH is 3.162 × 10-3 M, its pH is :(a) 8.5 (b) 9.5 (

1.	If molarity of NaOH is 3.162 × 10-3 M, its pH is :(a) 8.5 (b) 9.5 (c) 10.5 (d) 11.5
Answer» Correct Option is : (d) 11.5 NaOH is Strong base . It gives OH ion in solution. As we know, pH + pOH = 14 pH = 14 - pOH pH = 14 + log \([OH^-]\) pH = 14 + log \((3.162 \times 10^{-3})\) pH = 14 -3 + log (3.162) + \(log \ 10^{-3}\) pH = 14 - 3 + log (3.162) pH = 11 + 0.4996 pH = 11.5 Option : (d) 11.5

If molarity of NaOH is 3.162 × 10-3 M, its pH is :(a) 8.5 (b) 9.5 (c) 10.5 (d) 11.5

Answer»

Correct Option is : (d) 11.5

NaOH is Strong base . It gives OH ion in solution.

As we know,

pH + pOH = 14

pH = 14 - pOH

pH = 14 + log \([OH^-]\)

pH = 14 + log \((3.162 \times 10^{-3})\)

pH = 14 -3 + log (3.162) + \(log \ 10^{-3}\)

pH = 14 - 3 + log (3.162)

pH = 11 + 0.4996

pH = 11.5

Option : (d) 11.5