In 1985 benitoite became the california "state gemstone." found only in a tiny mine near coalinga, california, it is a silicate of barium and titanium with trace impurities that cause a range of hues from colorless to blue to pink. its general formula is bati(sio3)3. if a 15-carat stone were pure bati(sio3)3, how many moles of oxygen would it contain? (there are exactly 5 carats per gram.)

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution.calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.