[cool_dude]

Hi I am a grade 12 student and this is my first time posting a question here and hope someone can help out. The unit I am studying right now is chemical systems in equilibrium and I cannot answer one of the questions. If someone can help out that would be great

Question:
If 10.02 mL of 0.100 mol/L hydrochloric acid is required to neutralize 25.00 mL of a saturated calcium hydroxide solution. What is the concentration of the hydroxide ions present? What is the solubility of calcium hydroxide in mol/L?

Thanks in advance

[RickJ]

Welcome, cool_dude. I'll move this to homework help where it will be better received. Good luck with it!

[cool_dude]

I think I got the answer but I'm not 100% sure. I got 0.02004 M for the first part of the question which is the concentration of hydroxide ions. I still need help with the second part of the question

Can anyone please check my answer and maybe show me another way of doing this problem.

Thank you

[Capuchin]

So you have 1.002 mmol of H+ which will neutralise the same amount of OH-.

So the concentration of OH- is 1.002 mmol in 25 ml which is 0.04008 mol/l

As the formula for Calcium hydroxide is Ca(OH)2 you must have half as many moles of Ca(OH)2, i.e.. 0.501 mmol.

As the solution is saturated, we can argue that it is at the solubility limit, thus the solubility is given by:

0.501 mmol in 25 ml which is 0.02004 mol/l

Does that make sense? I'd like others to check and make sure I got it right, I'm a little rusty on this chemistry malarky :)

[cool_dude]

Thank you very much for the explanation. My teacher finally came back so I asked her to explain and yes my answer and your answer are correct.