a. What is the pH of a 6.1 ✕ 10-5 M Ca(OH)2 solution?
b. What is the H3O+ concentration of the solution?
I just cant figure out the ionic equation.
Perhaps this will help.
Ca(OH)2 ==> Ca^2+ + 2OH^-
Thanks! I got part A but how are you supposed to know the concentration of H30+ if its not in the equation?
See your follow up post above.
To determine the pH and H3O+ concentration of the given Ca(OH)2 solution, we need to understand its ionization in water and subsequent dissociation reactions.
The ionic equation for the ionization of Ca(OH)2 in water is:
Ca(OH)2 (s) → Ca2+ (aq) + 2 OH- (aq)
This equation represents the dissociation of Ca(OH)2 into calcium ions (Ca2+) and hydroxide ions (OH-) when it is dissolved in water.
To find the pH and H3O+ concentration, we need to consider the concentration of the hydroxide ion (OH-) in the solution.
Since Ca(OH)2 is a strong base, it dissociates completely in water. Therefore, the concentration of OH- ions is twice the concentration of Ca(OH)2.
a. pH of the solution:
To find the pH, we need to find the concentration of OH- ions first. Since the concentration of Ca(OH)2 is given, we can calculate the OH- concentration as follows:
OH- concentration = 2 × concentration of Ca(OH)2
Substituting the given value:
OH- concentration = 2 × (6.1 × 10-5 M)
Once we have the concentration of OH-, we can find the pOH using the formula:
pOH = -log[OH-]
Finally, the pH can be calculated using the formula:
pH = 14 - pOH
b. H3O+ concentration of the solution:
To find the H3O+ concentration, we can use the fact that water undergoes autoionization to produce equal concentrations of H3O+ and OH- ions. The concentration of H3O+ is therefore equal to the OH- concentration calculated above.
I hope this explanation helps you better understand how to find the pH and H3O+ concentration of the given Ca(OH)2 solution.