Question

(Double-weighted question) It takes 243 mL of 1.50 M HCl to completely dissolve a 10.0 g piece of metal. Is the metal platinum, copper, or manganese? Answer the question using two methods -a) titration and b) activity series.

Answer 1

(HCI] = 243 me = 0.243 Lite 1.50M nHCI = (0.243 x1-5) =) 0.3635 mol altitraction method Now let consider the meteel M WM = 10gm nu = 10/m mol MM M = mg/mol M + 2HCI MCI + 3H2 mole-mole analysis n = nHCl ) 10/m = 0.3645 m = 20 s /m = 54.ggmimol which is nearer to the molar Mass of manganese so the metal is manganese

b) Activity series method.:- In activity series : Reduction potential of copper and platinum is more than it so they can not reduce the Ht to H2 = where as Reduction potential of manganese is less than it so it can reduce ht to H₂. so the metal is manganese are