A chemist determined by measurements that 0.035 moles of magnesium participated in a chemical reaction. Calculate the mass of magnesium that participated in the chemical reaction. Be sure your answer has the correct number of significant digits.

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.