Heating an aqueous solution of a salt of this anion and sulfuric acid is used to measure the “[this anion] index” of water quality. The Kappa number of pulp is determined by measuring the consumption of a salt with this anion. A salt of this anion and osmium tetroxide are commonly used in the syn (-5[1])dihydroxylation of alkenes. Heating alkylbenzenes with an aqueous solution of a salt with this anion produces benzoates. A solution with this anion changes to a (*) brown color to show the presence of an unsaturated carbon-carbon double bond in Baeyer’s test. Due to the +7 oxidation state of its central atom, this anion is a (-5[1])strong oxidizing agent when bonded to potassium. For 10 (10[2])points, purple solutions are produced by what polyatomic anion composed of four oxygens around a manganese (10[1])atom? (10[1]0[3])■END■