Any one please help me ASAP Identify following substance as Lewis acid and bases??? NH3 , F (negative sign on top) ,H2O : BF3

Achemistry student weighs out of phosphoric acid , a triprotic acid, into a volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with solution. calculate the volume of solution the student will need to add to reach the final equivalence point. round your answer to significant digits.

What is the number of atoms in 3.54 mol s

What are transitions between a liquid and a solid called? identify which way they are transitioning