Question

Question: you have a clear, colorless aqueous sample in a beaker that contains either CO2^-2(aq) or C^-1(aq) or a mixture of both ions. the following aqueous reagents are available: NaCl, HNO3, and AgNO3. describe a procedure that will allow the determination of which of the three solution compositions is correct.

I' not sure how to use it when there is a mixture of both ions. For the other mixtures i know that NaCl will not react with either. the AgNO3 is mixed with the unknown solution in the beaker. a percipitate will form. The percipitate is either AgCl or Ag2CO3. The percipitate should than be placed in a beaker and reacted with HNO3. if no reaction occurs the percipitate is AgCl and the unknown solution contained Cl^-. If evidence of a reaction occurs (bubbles form) Ag2CO3 was the percipitate and the unknown solution contained CO3^-2.

What do i get when their is a mixture of both ions?

Answer 1

I am really confused by the notation. I don't know of many CO2^-2 or C^-1. Could that be CO3^-2 and Cl^-1? If so, it makes a BIG difference.

Answer 2

Ya sorry it means CO3^-2 and Cl^-1

Answer 3

You're ok with what you have. For a mixture of the two, take a fresh sample and add HNO3. If bubbles appear (evidence of CO3^-2) allow them to dissipate, then add a little more HNO3 to make sure all of the CO3^- has been displaced with the acid. Heat the solution to drive off any dissolved CO2 in the aqueous solution. Let the solution cool, then add AgNO3. If a ppt forms, that is evidence of chloride since AgCl is not soluble in HNO3.