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pleace
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Homework Statement
15.1g of calcium hydroxide completely dissociates in distilled water forming 855ml of basic
solution.
a) Dissociation Equation
b) Calculate the concentration of OH in the solution
c)Calculate the pH of the above solution
Homework Equations
c=n/v
pH=-log[H]
The Attempt at a Solution
a) Ca(OH)2 (s) = Ca2+ + 2OH -
i think that equation is right?
b) using molar mass ofCa(OH)2 and 15.1g, the moles of Ca(OH)2 is around 0.2moles.
since Ca(OH)2 and OH are in 1:2 ratio, then there is 0.4 moles Oh.
c=n/v
c=0.4/0.855 =0.452 mol/L(DO i use 0.855L for the volume even tho that includes the entire basic solution which is Ca2+ + 2OH - ?)
c) Now this is the part where i am really unsure about.
pH = -log[H], but since i want to find the entire solution's pH, what concentration do u use? do i divide 0.452/2=0.226
and then go -log0.226 = 0.64.
Thank you so much if you try to help me :)