A common constituent of kidney stones is Ca3(PO4)2, calcium phosphate. Are kidney stones containing Ca3(PO4)2 more likely to form when the urine is acidic or when it is basic? Explain.
To determine whether kidney stones containing Ca3(PO4)2 (calcium phosphate) are more likely to form in acidic or basic urine, we need to understand the solubility of calcium phosphate under different pH conditions.
In general, the solubility of calcium phosphate decreases as the pH increases (stomach acid being the exception). This means that calcium phosphate is more soluble in acidic environments than in basic ones.
When urine is acidic, it has a lower pH value (below 7 on the pH scale). Under acidic conditions, the solubility of calcium phosphate increases, making it less likely for kidney stones containing Ca3(PO4)2 to form. This is because the higher solubility allows the calcium and phosphate ions to remain dissolved in the urine rather than solidifying and forming crystals.
On the other hand, when urine is basic, it has a higher pH value (above 7 on the pH scale). In basic conditions, the solubility of calcium phosphate decreases, making it more likely for kidney stones containing Ca3(PO4)2 to form. The lower solubility promotes the precipitation of calcium and phosphate ions, leading to the development of solid crystals, which can eventually aggregate and form kidney stones.
Therefore, kidney stones containing Ca3(PO4)2 (calcium phosphate) are more likely to form when the urine is basic rather than acidic.