Tides are the rise and fall of surface levels of Earth's ocean water caused by the gravitational effects of which two celestial objects? A)stars and planets
B)comets and meteors
C)earthquakes and volcanoes
D)moon and sun

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.