Question

Calculate the pH of a solution made by dissolving 10 grams of sodium hydroxide in 1000 mL of Water?

Answer 1

10.4 is the pH of a solution made by dissolving 10 grams of sodium hydroxide in 1000 mL of Water.

Step-by-step explanation:

Data given:

volume of water or solution = 1000 ml or 1 L

mass of NaOH = 10 grams

molarity =?

pH =?

atomic mass of NaOH = 40 grams/mole

MOLARITY is calculated by using the formula:

molarity =
`(number of moles)/(volume of the solvent)`

number of moles

n =
`(mass of solute)/(atomic mass)`

n =
`(10)/(40)`

= 0.25 moles of NaOH

now molarity or concentration is calculated by using the formula:

molarity =
`(0.25)/(1)`

0.00025 M is the molarity.

pOH = - log(0.00025)

pOH = 3.60

pH is calculated as:

14 = pH + pOH

pH = 14-pOH

= 14 - 3.60

= 10.4 is the pH of the NaOH solution.