Chapter 17, Problem 17.145MP

One type of kidney stone is a precipitate of calcium oxalate ( $Ca{C}_2{O}_4,{\text{ K}}_{sp}=2.3\times {10}^{-9}$ ). A urine sample has a $C{a}^{2+}$ concentration of $2.5\times {10}^{-9}$ M and an oxalic acid ( $H_2{C}_2{O}_4,K_{a1}=5.9\times {10}^{-2}\text{,}{K}_{a2}=6.4\times {10}^{-5}$ concentration of $1.1\times {10}^{-4}$ .

1. A typical pH for urine is 5.5. Will a precipitate of calcium oxalate form under these conditions?
2. A vegetarian diet results in a higher pH for urine, typically greater than 7. Would kidney stones he more or less likely to form in urine with a higher pH?