Answer to Question #163340 in General Chemistry for mike

Question

Elizabeth is asked to determine the quantity of antimony in a sample using an oxidation-reduction titration with an oxidising agent. She used a 9.62g sample of stibnite, an ore of antimony, and dissolved it in hot, concentrated HCl(aq) and passed it over a reducing agent so that all the antimony was in the form Sb3+. The Sb3+(aq) was completely oxidised by 43.70mL of a 0.1250M solution of KBrO3. Help her calculate the amount of antimony in the sample and its percentage in the ore.       

The unbalanced equation is:

BrO3¯(aq)    +    Sb3+(aq)     ⇨     Br¯(aq)    +    Sb5+(aq)

Answer 1

The amount of antimony in the sample = 0,0164 mol

Percentage in the ore = 20,74%