Question

Calculate the pH of a 0.0350M

NaOH solution. Assume NaOH
dissociates completely in water.
pH

Answer 1

12.54

Step-by-step explanation:

The dissociation equation of NaOH is given below:

NaOH <==> Na+ + OH-

Molarity of NaOH = 0.0350M

From the equation,

Since 1M of NaOH produced 1M of OH-, then, 0.035M of NaOH will also produce 0.035M of OH-..

From the above,

[OH-] = 0.035M

Now, we can solve the pH by doing the following:

pOH = — log [OH-]

pOH = — log 0.035

pOH = 1.46

Recall

pH + pOH = 14

pH = 14 — pOH

pH = 14 — 1.46

pH = 12.54

Answer 2

pH = 12.544

Step-by-step explanation:

• NaOH → Na+ + OH-

0.0350M 0.0350M 0.0350M.........equilibrium

∴ pOH = - log [OH-]

∴ pH + pOH = 14

⇒ [OH-] = 0.0350 M

⇒ pOH = - Log (0.0350)

⇒ pOH = 1.456

⇒ pH = 14 - 1.456

⇒ pH = 12.544