Respuesta :
Answer:
0.07 M
Explanation:
We have to start with the reaction between the Calcium hydroxide and the Hydroiodic acid:
[tex]Ca(OH)_2~+~HF~->~CaF_2~+~H_2O[/tex]
Then we have to balance the reaction:
[tex]Ca(OH)_2~+~2HF~->~CaF_2~+~2H_2O[/tex]
We have to keep in mind that we have to do use the volume in "L" units (14.7 mL= 0.0147L). When we plug the values into the equation we will get:
[tex]M=\frac{#mol}{L}[/tex]
[tex]0.164~M=\frac{#mol}{0.0147}[/tex]
[tex]#mol=~0.0024[/tex]
Now, we have to use the information from the balanced reaction to finding the moles of Calcium hydroxide. When we check the reaction we found a molar ratio of 1:2 ( 1 mol of [tex]Ca(OH)_2[/tex]: 2 mol of [tex]HF[/tex]). With this molar ratio, we can find the moles of [tex]HF[/tex].
[tex]0.0024~mol~HF\frac{1~mol~Ca(OH)_2}{2~mol~HF}[/tex]
[tex]0.0012~mol~Ca(OH)_2[/tex]
Finally, to find the molarity we have to divide the moles of [tex]Ca(OH)_2[/tex] and the volume of [tex]Ca(OH)_2[/tex] in liters (17.2 mL=0.0172L) so:
[tex]M=\frac{0.012}{0.0172}=0.07[/tex]
The molarity of [tex]Ca(OH)_2[/tex] is 0.07M.
