Question

How much naoh is needed to prepare 461 ml of solution with a ph of 10.00?

Answer 1

Answer: -

Volume of NaOH = 461 mL = 461/1000 = 0.461 L

pH = 10.0

Using the relation pH + pOH = 14.00

pOH = 14.00 - 10.00= 4.00

Using the relation

[OH⁻] = $10^{-pOH}$

= $10^{-4.00}$ M

Since NaOH is a monobasic acid,

[NaOH] = [OH⁻] = $10^{-4.00}$ M

Amount of NaOH = [NaOH] x Volume of NaOH

= $10^{-4.00}$ M x 0.461 L

= 4.61 x 10⁻⁵ mol

Molar mass of NaOH = 23 x 1 + 16 x 1 + 1 x1

= 40 g / mol

Mass of NaOH required = 4.61 x 10⁻⁵ mol x 40 g/ mol

= 1.84 x 10⁻³ g