Working as a summer student for the ministry of natural resources you are responsible for testing the water in a creek near an industrial site for the presence of
the toxic metal ions lead (II) and mercury (II) in the water. Design an experiment to
sequentially test for the presence of lead (II) and mercury ions as well as the non-toxic
magnesium ion. Assume the water sample does not include any other interfering ions.
Show the net ionic equations for the precipitation reactions that might occur.

Compare and contrast physical changes with chemical changes.

Salicylic acid is a very important acid. it is used to synthesize the aspirin by treating with acetic anhydride. a 0.2015-g sample of salicylic acid was dissolved in a 100.00-ml volumetric flask, and the solution was diluted to the mark. a 10-ml aliquot of this solution was titrated with standard naoh (0.01130 + 0.2% n) to a phenolphthalein faint pink color end point at 19.81 ml. (a) (calculate the normality of the salicylic acid solution used in the titration. (b) assuming the salicylic acid is pure, what is the equivalent weight of the salicylic acid? practice problems for the final exam (continued) (c) (calculate the inherent error in the determination of the equivalent weight you calculated in part (b). use the following absolute errors in the equipment /glassware when calculating the inherent error. 5.00-ml pipet: + 0.02 ml 100-ml volumetric flask: + 0.08 ml analytical balance: + 0.2 mg 25-ml buret: + 0.03 ml

What is the subscript for oxygen in its molecular formula