a) How many grams of MgCl2 are needed to prepare 500 mL of a solution with a concentration of 0.35 M 3 . b) What is the concentration of chloride ions in the stock solution? e) How many mL of the stock solution is needed to prepare a 250 mL of 0.100 M MgCl2 dilution? In an experiment, a titration was conducted in order to determine the concentration of a solution sulfuric acid. A 20.0 mL sample of this acid is placed in an Erlenmeyer flask and two drops of phenolphthalein were added. An accurately zeroed buret containing 0.095 M potassium hydrox- used to deliver potassium hydroxide solution to the flask until the palest, persistent pink color w observed. The final buret volume is 18.50 mL. Answer the following questions about this titrat a) Write the balanced molecular reaction that took place in this titration. b) What is the molar concentration of the sulfuric acid solution, as determined from this titratie