1. what is the primary standard used in this experiment? what is the molar mass of the primary standard? 2. use the chemical formula for the primary standard to write the chemical reaction for the standardization of potassium permanganate. 3. what will indicate the endpoint of the titration? 4. a 0.495 g sample of iron containing salt required 20.22 ml of 0.0194 m permanganate solution to reach the endpoint of a titration. what is the percent of iron (55.845 g/mol) in the salt?