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NAME DATE. SECTION_Tuesday SECTION POSTLABORATORY ASSIGNMENT A 1. An “iodide/chl

ID: 589177 • Letter: N

Question

NAME DATE. SECTION_Tuesday SECTION POSTLABORATORY ASSIGNMENT A 1. An “iodide/chloride/sulfate" unknown solution gave a yellow precipitate with aqueous AgNO,. The supernate did not react with Ba(NO.),. A portion of the yellow precipitate dissolved in aqueous NH,OH. After centrifuging, the supernate was acidified with HNO,, which gave a white precipitate. State the ion(s) present in the unknow solution. TIT 2. An “iodide/chloride/sulfate” unknown solution gave no reaction with aqueous AgNO,. However, the unknown solution produced a white precipitate with aqueous Ba(NO3),. State the ion(s) present in the unknown solution. 3. Write the formula for each of the following anions. Refer to Appendix.

Explanation / Answer

1. The unknown ion is Bromine.

AgNO3 + NaBr ---> AgBr + NaNO3

It gives Yellowish ppt of AgBr on reaction with AgNO3, which is slightyl soluble in dil. NH4OH due to complex formation.

AgBr + NH4OH ---> Ag(NH3)2Br + 2H2O.

The supernatant with contains the nitrate ion will not react with barium nitrate.