Question

A solution contains Al and Co2+. The addition of 0.3806 L of 1.750 M NaOH results in the complete precipitation of the ions as Al(OH), and Co(OH), The total mass of the precipitate is 23.68 g. Find the masses of Art and Co?" in the solution mass of Art: 3.00 mass of Coat: 9.44

Answer 1

General concepts of steochiometry in chemical reactions have been used to solve the problem.
let solution contains x and y moles of Alst and co²t respectively. addition of 0.38062 of 1.750 m MooH add (0.38 06 X 1.750) moles of NaOH in the solution = 0.6660 moles of Naot a odded in the solution for complete precpitation of Al (OH)3 and Co@t) 2 In solotan Al3+ + 3 Not OH - Al(OH)3 + 3Nat Co2+ + 2 Mat ou Co (OH)₂ + 2Nat 3 moles of or reset coth & moles of Alet ne moles of art reaks worth of a note of 627 Hene, 0.6660 moles of ott forned from NGOtta reacts with anodes of Art and y'ndes cort ² 34+ 2y = 0-6660 - ③ Molecular most of Al(OH), = 78g/mol Molecular moss of COCOH)2 = 92-94g/mol Total mass sont precipitate must be = 78 x + 92-944 Total mas given precpitate = 23.68g

784 +92.914 = 23-68 - @ Salving equation and we get a=o.lls moles y = 0.155 moles - Moss of A13t present in selotion : (0.118 x 26-18) = 3-183 grams & (xx.26.98) grans present in solution = (4 x 58.93) groms & (0.155 * 5893) g = 9.134 grams