Determine the density of chlorine gas at 22c and 1.00 atm pressure

Ineed with a, b, c, d, and e on the long answer

Between 2014 and 2016, more than 25,000 children in flint, michigan, drank water that was contaminated with lead from lead pipes. during this time, the city claimed the water was safe to drink. which of these actions could the city have taken to ensure that the drinking water was free from lead?

What is the molar mass of potassium nitrate, kno3