Solutions: 2001 D By: I Schnizzle

2001 D Part A .1M Pb(NO3)2 /.1M NaCl /.1M KMnO4 /.1M C2H5OH / .1M KC2H3O2 A.) Which solution has the highest boiling point? Explain The answer to this question can be found by referring back to the bond strengths within each of these solutions. The bond strength of any of these solutions determines how high or low the boiling point will be.

2001 D Part A Cont’ Since bonds within ionic compounds are stronger than those within covalent compounds the .1M of C2H5OH is out. Than looking at your other four solutions which are ionic Pb(NO3)2 has the most ions of the remaining four solutions there for it will have the highest boiling point.

2001 D Part B .1M Pb(NO3)2 /.1M NaCl /.1M KMnO4 /.1M C2H5OH / .1M KC2H3O2 B.) Which solution has the highest pH? Explain The pH level of any solution is determined by how basic or acidic the solution is. If a solution has a weak acid and a salt it will form a more basic solution. This goes for a salt and weak base as well except the solution would be more acidic

2001 D Part B Cont’ KC2H3O2 is the solution that will have the highest pH based on the weak acid and salt it has. When KC2H3O2 is added to H2O the compound will dissociate and the weak acid and salt, K in this case will form new compounds. With the new compound formed from the weak acid the new solution will be more basic, and in turn have higher pH.

2001 D Part C .1M Pb(NO3)2 /.1M NaCl /.1M KMnO4 /.1M C2H5OH / .1M KC2H3O2 C.) Identify a pair of solutions that would produce a precipitate when mixed together. Write the formula of the precipitate. In order to complete this question you must first have a general understanding of your solubility rules.

2001 D Part C Cont’ After looking over your solubility rules you will find that Pb2+ does not tend to dissolve with most salts. Therefore the solutions of Pb(NO3)2 and NaCl are good solutions that will form a precipitate since the ions will form new compounds one of which is PbCl2 which is insoluble.

2001 D Part C Cont’ The equation for this new precipitate formed would be as follows. Pb(NO3)2 + NaCl yields NaNO3 + PbCl2 After balancing this equation the final balanced equation would be Pb(NO3)2 + 2NaCl yields 2NaNO3 + PbCl2 Where the PbCl2 is the precipitate formed and is also the formula of the precipitate.

2001 D Part D .1M Pb(NO3)2 /.1M NaCl /.1M KMnO4 /.1M C2H5OH / .1M KC2H3O2 Which solution could be used to oxidize the Cl-(aq) ion? Identify the product of the oxidation. In order to oxidize something the charge on the ion becomes more positive so the goal is to find a solution that allows for Cl-’s charge to become more positive.

2001 D Part D Cont’ KMnO4 is a perfect solution for this oxidation to occur because once the ions of the KMnO4 are broken down they will oxidize the Cl- the most. This oxidation occurs and forms the product of ClO3- which gives the Cl- a more positive charge of 5+

2001D Part E .1M Pb(NO3)2 /.1M NaCl /.1M KMnO4 /.1M C2H5OH / .1M KC2H3O2 E.) Which solution would be the least effective conductor of electricity? Explain. First of all good conductors of electricity are compounds that have ionic bonds within them as opposed to covalent bonds. So we are looking for a covalent bonded compound since that would be the least effective solution to conduct electricity.

2001D Part E Cont’ C2H5OH is the only compound that has covalent bonds and therefore does not form any ions in H2O. Since H2O is also covalently bonded the solution would be the least likely to be a good conductor of electricity.

BAM! The End