Question

A solution contains all and Co. The addition of 0.3636 L of 1.752 M NaOH results in the complete precipitation of the ions as Al(OH), and Co(OH),. The total mass of the precipitate is 23.07 g. Find the masses of Art and Co2+ in the solution. mass of Al mass of Co2+ TOOLS x10

Answer 1

- Meles of Nach added = Molarity X volume (lit.) = 10752 x 0.363.6 - 0.637 males A13+ and co²t will react as; - Al3+ + 3NaOH = AICOH)3 + 3Net Co²t + 2NaOH = Color J + anat

Suppose, moles of Alat in solution = n moles of co2t in solution = m _SO;__ moles of NaOH heasted with A13+ = 37 ---- moles of Raoh reacted with cozt =3m but total available moles of NQOH = 0.637 - So; 3nt3m should be equal to 0.637 or M+M = 0.212) - D Now, moles of Allohh fermed according to --8toichio retrey of Freaction_sn Similarly, moles of cocoH), formed = m so, mase of ALCOH)2 = molesx molar mass = nx 78 =78n gm mass of COCOH), -_ mx 93 = 93m_3 but, given mass of total pkt = 23.07.9m so 1789_+93 m = 23.07 - 12) solving eqh (1) 8 (2) 93n +93 m & multiplying the from (1) = = 19.716 T equis by 93). brom (2) 78. n tg3m = 23.07 15 n = 3.354 vor in the Tatue of moles (1) can not be negative. so there is some poor in the au me bossibility take cacOHI2 insted on OH)2 insted of CO(OH)2 questions