Question

What is the pH of a 0.08 M solution of Ca(OH),?

Answer 1

Answer:

pH = 12.20

Explanation:

Ca(OH)2 is a strong base, so it dissociates completely. A 0.08 M solution of Ca(OH)2 is 0.16 M OH-, since every mole of Ca(OH)2 has 2 OH-.

Calculate pOH using [OH-] = 0.16 M

pOH = -log(0.16) = 0.80

pH = 14 - pOH = 14 - 0.80 = 12.20

Answer 2

Taking into account the definition of pH and pOH, the pH of a 0.08 M solution of Ca(OH)₂ is 13.21

pH

First of all, pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.

The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:

pH= - log [H⁺]= - log [H₃O⁺]

pOH

Similarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:

pOH= - log [OH⁻]

Relationship between pH and pOH

The following relationship can be established between pH and pOH:

pOH + pH= 14

This case

A strong base is one that dissociates completely in water, that is, it contributes the maximum number of OH- ions.

Ca(OH)₂ is a strong base that for each Ca²⁺ cation there are two OH⁻ anions and in which for each mole of Ca(OH)₂ two moles of OH⁻ are formed.

So: [OH⁻]= 2×[Ca(OH)₂]

[OH⁻]= 2×0.08 M

[OH⁻]= 0.16 M

Replacing in the definition of pOH:

pOH= - log (0.16 M)

Solving:

pOH= 0.79

Finally, considering the relationship between pH and pOH:

0.79 + pH= 14

pH= 14 - 0.79

pH= 13.21

In summary, the pH of a 0.08 M solution of Ca(OH)₂ is 13.21

Learn more about pH and pOH:

brainly.com/question/16032912?referrer=searchResults

brainly.com/question/13557815?referrer=searchResults