Periodic table of elements

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.

Achemical reaction is done in the setup shown , resulting in a change of mass. what will happen if the same reaction is done in a sealed container that is placed on the electronic balance?

Need , hurry pls create a superhero out of the element iron, what are its powers and his sidekick ( an element that works well with iron). how was the superhero made and who discovered him