Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A solution containing a mixture of metal cations was treated with dilute HCI and

ID: 854639 • Letter: A

Question

A solution containing a mixture of metal cations was treated with dilute HCI and no precipitate formed. Next, H2S was bubbled through the acidic solution. A precipitate formed and was filtered off. Then, the pH was raised to about 8 and H2S was again bubbled through the solution. A precipitate again formed and was filtered off. Finally, the solution was treated with a sodium carbonate solution, which resulted in no precipitation. Which metal ions were definitely present, which were definitely absent, arid which may or may not have been present in the original mixture? Definitely present Definitely absent Possibly present

Explanation / Answer

definitely not presen:Pb+2 , Ag+ , Hg2+2( they form ppt with HCl), Mg+2 , Ba+2 (form [ppt with carbonate)

Definitely present: Hg+2 , Cd+2 , Sn+4, Sb+3 (ppt in acidic H2S), Fe+3, Cr+3, Zn +2 (ppt in basic H2S) ,

May be: K+ (soluble in carbonate)

Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Drop an Email at
drjack9650@gmail.com
Chat Now And Get Quote