The Alkaline Earths and the Halogens: Two Families in the Periodic Table
1. All of the common noble gases are monatomic and low-boiling. Their boiling points in °C are: Ne, –245; Ar, –186; Kr, –152; Xe, –107. Using the Periodic Table, predict as best you can the molecular formula and boiling point of radon, the only radioactive element in this family.
Molecular FormulaBoiling Point
1. Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is red, and C is yellow. In the reactions in which they participate, they are reduced to A-, B-, and C- ions respectively, all of which are colorless. When a solution of A is mixed with one containing B- ions, the color changes from green to red. |Which species is oxidized? | | |Which is reduced? | |
2. When a solution of A is mixed with one containing C- ions, the color remains green. |Is A a better oxidizing agent than B? | | |Is A a better oxidizing agent than C? | |
3. Arrange A, B, and C in order of increasing strengths as oxidizing agents.
4. You are given an unknown, colorless, solution that may contain only one salt from the following set: NaA, NaB, NaC. In solution each salt dissociates completely into the Na+ ion and the anion A–, B–, or C–, whose properties are given in Problem 2. The Na+ ion is a spectator ion. Given the availability of solutions of A, B, and C, develop a simple procedure for identifying the salt that is present in your unknown. Use the other side of this page.