2. A solution was prepared by dissolving 477 mg of potassium sulfate (K2SO4) in 749 mL of water. Calculate: mmols of K2SO4 in 50 mL of the solution B. Should the concentration of K2SO4 be described with Formal? Why or why not? C. Concentration of K2SO4 (in mM and in ppm) D. Concentration of K+ (mM and ppm) E. Concentration of SO42- (mM and ppm) F. % (w/v) which is percent weight by volume

3. Find the answer to the equation below including the absolute and relative uncertainty. Include significant figures and do not round until the end. State an example of when you would need to propagate uncertainty in this way. [9.8 ( 0.3) 2.31 ( 0.01)] divided by 8.5 ( 0.06)

4.In a new method for determining selenourea in water, the following values were obtained for tap water samples spiked with 50 ng ml-1 of selenourea: 50.4, 50.7, 49.1, 49.0, 51.1 ng ml-1 Aller, A.J. and Robles, L.C., 1998, Analyst, 123: 919. A. Is this new measurement reporting correctly at a 95% confidence level?