Question

A student was given a solid containing a mixture of nitrate salts. The sample completely dissolved in water, and upon addition of dilute HCI, no precipitate formed. The pH was lowered to about 1 and HS was bubbled through the solution. No precipitate formed. The pH was adjusted to 8 and HS was again bubbled in. This time, a precipitate formed, Which compounds might have been present in the unknown? Zn(NO), Fe(NO), Ca(NO), AgNO, Sn(NO) NaNO, Bi(NO), CH(NO),

Answer 1

ANL 0 ON Based on lepon cations of these separates cations in groups according Expt. No Sollcbteities or their composed salts to we the ho 626uf I 5 Agtr Pe72, 1972 These cottone Bo duce insoluble chloridele so they can be precipitated with dieute hel. While all Lother nations Remain in solution Go-step-7's These catione (com be cuta, Bi+2, cate o As t3 sbt sont produce rese inseable sulfides, so they precipitated by low amount of Hose Cookup -IT) → aet, corte cat2, Feta, z2t2, Nit, cor, Phat 17hese_patos Boduce seiently soluble sceltider rkse value more than 10-20). so they can be I Precipitated by high amount of Has. I coobux -N Not, kt, N4U* These cations do not helpitate with Religente any of the Hence in woven options oney Izn (NO3)2 FOLNO3)2 Ca(NO3)2 ... core follos 've senesio. , co (NO3)2 Goorepad 0972, M82, Spit 2, these cations can be precipitated by the addition of carbonate once the long of the Bigst three groups bove been removede Hence Cecnozalso Abelove given resseeria, Date - Teacher's Signature :

Are o In general the fellubiertos Loewe Šeelds containing amion (conjugade ease on o der acids such as hydrovejde, acetate, corrbonate a phosphate and see fl de mereape In the acidic solution than in pure water. Morie in civem op+/038,9.. oney edcord and Basoz will be more greuble im an acidic solution thom in pure waters. Because - a salid cu I dag dissociates into cata and Irl The Irion formed is a weak conjugate Base of a Stoong acid. Thus sollbleky Oth cuI does not merele im acidic solution. Similarly for other options. The (67 kccoy t ikt & clour weak CiB of by strong teloy a old. C) Basos Bath + 503-2 strong C.B of beak H2303 Quid, (@) cucoH)2 f cut2*204 strong coB of a weat acid. е) са го н а пQ + 2 + roy-2 аэ ерек е.В. ога sitoong H2SO4 acids since only strong conguesade Buse will be more Bollible im. quidic Solutions thus, ones Baso3 and Cucou salt are more souble Im acidic sulation tham in puoe water.