Reference no: EM13125259

Thermochemistry and Periodic Properties of Elements
1. State which atom is larger according to periodic trends. Explain the difference for each of the pairs.
a) Br, F
b) Ca, Mg
c) C, Si
d) He, Ar

2. State which atom has a smaller first ionization energy according to periodic trends. Explain the difference in ionization energy for the pairs.
a) O, S
b) K, Na
c) Cd, Zn
d) Al, Ga

3. Which of the following is smaller? Explain the trend.
a) Mg, Mg2+
b) Al, Al3+
c) Cs, Cs+

4. Arrange in order of increasing size and explain the trend.
a) Fe, Fe 2+, Fe3+
b) Ti, Ti3+, Ti4+

5. Arrange in order of increasing size:
Br-, Ca2+, Cl-, F-, Li+, Mg2+, N3-, Na+, O2-, Rb+, S2-

6. Given the following data:
2NO(g) ---> N2(g) + O2(g) (delta)H= -180.6 kJ
N2(g) + O2(g) + Cl2(g) -----> 2NOCl(g) (delta)H= +103.4 kJ
Find the ?H for the following reaction:
2NOCl(g) ----> 2NO(g) + Cl2 (g)

7. During the discharge of a lead-acid storage battery, the following chemical reaction takes place:
Pb + PbO2 + 2H2SO4 ----> 2PbSO4 + 2H2O
Using the following two reactions:
Pb + PbO2 + 2SO3 ------> 2PbSO4 (delta)H(degrees)= -775 kJ
SO3 + H2O ---> H2SO4 (delta)H(degrees)= -113 kJ

Determine the enthalpy of the reaction for the discharge reaction above.

*The delta triangle symbol and the degrees symbol are written out.