Kidney stones are composed of crystals of calcium oxalate, CaC2O4. The solubility of CaC2O4 is

I am doing a lab report involving limiting reactants and percent compostition. The reactans are calcium chloride dihydrate and potassium oxalate monohydrate, which yeilds calcium oxalate monohydrate. My question is which product should i choose as my varied amount when doing my experiment that will yeild the best results of calcium oxalate monohydrate?

To find the pH of a saturated solution of calcium oxalate, we need to calculate the concentration of hydroxide ions (OH-) in the solution.

The solubility of CaC2O4 is given as 6.7 x 10^-5 g per 100 ml of solution. We can convert this to mol/L by dividing by the molar mass of CaC2O4 (40.0 + 12 + (16 x 4) = 128.0 g/mol) and multiplying by 1000 (to convert mL to L).

So, the solubility of CaC2O4 in mol/L is:

(6.7 x 10^-5 g / 100 mL) * (1 mol / 128.0 g) * (1000 mL / 1 L) = 5.234 x 10^-7 mol/L

Since calcium oxalate (CaC2O4) is a sparingly soluble salt, it dissociates in water to release calcium ions (Ca2+) and oxalate ions (C2O4^-2). This means the concentration of Ca2+ and C2O4^-2 ions in the saturated solution will be equal.

Therefore, the concentration of Ca2+ ions (and C2O4^-2 ions) in the saturated solution is:

5.234 x 10^-7 mol/L

Now, to find the concentration of hydroxide ions (OH-) in the solution, we need to consider the dissociation of water. Water molecules can undergo autoionization to produce equal concentrations of hydrogen ions (H+) and hydroxide ions (OH-). In pure water, the concentration of H+ and OH- ions are both 1 x 10^-7 mol/L.

Since the Ca2+ ions will react with the OH- ions to form a precipitate of Ca(OH)2, we can assume that the OH- ions from water will be completely consumed by the Ca2+ ions. Therefore, the concentration of OH- ions in the saturated solution will be equal to the concentration of Ca2+ ions.

Now, we can calculate the pOH of the saturated solution:

pOH = -log[OH-] = -log(5.234 x 10^-7) ≈ 6.28

Finally, we can find the pH of the saturated solution using the relationship:

pH + pOH = 14

pH + 6.28 = 14

pH ≈ 7.72

Therefore, the pH of a saturated solution of calcium oxalate is approximately 7.72.