ch. 6 & 7  atomic orbitals & periodic trends                  [80 points]                  AP Chemistry

For problems involving calculations, show your work in an organized manner, include any relevant formula / equation, the proper units in your work / answer, proper number of signficant figures in your answer.

1.  fill-in the blank  [10 points]

a.  Na  +  H₂O  -->  ________

b.  CO2  +  H₂O  -->  ________

c.  Ca  +  H₂O  -->  _________

d.  Na  +  Cl₂  -->  _________

e.  Na  +  O₂  -->  _______

2.  What is the electron configuration and orbital diagram of :  [20 points]

a.  sulfur

b.  arsenic

3.  What is the frequency of light in the hydrogen emission sprectra corresponding to the transition involving the n=2 and n=3 electronic energy levels ?  [10 points]

4.  What is the trend in the atomic size of elements within a column in the Periodic Table ?  Rationalize your answer.  [10 points]

5.  The first ionization energy of nitrogen and oxygen are 1402 and 1314 kJ/mole, respectively.  Rationalize this observation.  [10 points]

6.  A solution of Ni²⁺ is green.  Which color of light, green or blue, would be best to determine the concentration of Ni²⁺ in a sample ?  Justify / rationalize your answer.  [10 points]

7.  old topic:  What is the value and units of k in terms of moles, liters, and seconds ?  [10 points]

rate = k [A]^1/2 [B] [C]²

where rate = 85.0 millimolar / second;  [A] = 25 molar;  [B] = 2.0 molar;  [C] = 2.0 molar;  molar = moles / liter.