In experiment #1 the main objective is to test the solubility and the strength of the ionic compounds that are formed during titration. Solubility is a measure of the degree at which a compound is able to dissolve. Titration is used in this experiment to determine the Ksp of the saturated solution of Mg(OH)2 Ca(OH)2 SR(OH)2.
Procedure and Observations
Saturated solutions of Mg(OH)2, Ca(OH)2, and Sr(OH)2 are all prepared in which they need to be diluted with distilled water after phenothelain is added to the saturated solutions described above. Since the solution is basic when the phenothelain is added a pink color is observed titrate it with HCL to find the equivalence point, which a clear color is shown. In each titration a pink color is observed and once HCL is added the equivalence point is reached the pink color disappears.
Results
Trial Mg(OH)2 (mL) HCl
(mL) HCl
(moles) Mg(OH)2
(moles) OH-
(moles) Mg2+
(moles)
1 50mL 7.70mL 0.0000154 0.0000077 0.0000154 7.7x10-6
2 50mL 7.95mL 0.0000159 0.00000795 0.0000159 7.95x10-6
3 50mL 7.90mL 0.0000158 0.0000079 0.0000158 7.9x10-6
Trial OH-
(M) Mg2+
(M) Ksp Average OH- (M) Average
Ksp
1 2.669x10-4 1.33x10-4 9.46x10-12 2.713x10-4 9.99x10-12
2 2.743x10-4 1.37x10-4 1.031x10-11
3 2.728x10-4 1.36x10-4 1.02x10-11
Figure 1. Titration of Mg(OH)2
Figure 1 displays the titration that’s was performed on Mg(OH)2 and HCl. A standard solution of 0.002M of HCl was titrated with a saturated solution of Mg(OH)2 distilled. The following reaction displays the titration.
2HCl + Mg(OH)2 -> MgCl2 + 2H2O. The titration is helps us find both the concentration of Mg(OH)2 , once that is found OH-, which in turn helps us find Ksp.
Ksp=[Mg2+][OH-]2. The above formula shows the description to find the Ksp
The average concentration of the OH- solution is and the average solubility of the solution is
Figure 2. Titration of Ca(OH)2
Figure 2 displays the titration that was