Practice midterm questions for Chem 101 Section J1, Fall 2004

1. Supply the missing name or formula:

palladium (II) phosphate ____________________________________

strontium nitrate hydrate ____________________________________

_______________________________ N₂O₄

_______________________________ Fe(ClO₄)₃

cadmium phosphide _____________________

mercury (I) chlorate _____________________

_____________________ TlCH₃COO

_____________________ HBrO(aq

2. Answer the following by filling in each blank with the appropriate answer, or by circling the correct choice, as appropriate.

a) Which is the stronger oxidizing agent, Pb(IV) or Pb(II)? ____________

b) Which element has a larger sixth ionization energy, P or S? ____________

c) The bonding within the compound SbF₅ is primarily ionic / covalent? (Circle one)

d) The electron affinity of groups 2 and 18 is close to zero. Which other group (in the s and p blocks) has an electron affinity which is smaller than would be expected on the basis of the general trends? _____________________

f) Identify the neutral element that is isoelectronic with the cation Po⁴⁺. _______________

g) Which atom has the greater Z_eff, Si or S? __________

h) Which ion has the largest radius, K⁺, Cl^-, Sc³⁺ or

S^2-?_____________________.

i) Arrange the following atoms in order of decreasing atomic radius:

In, Te, Sn, Kr ___________________________________.

j) A new element is discovered. It has two isotopes. The relative abundances of the isotopes and their masses are 18 % isotope 1, mass 350.0 g/mol and isotope 2, mass 352.0 g/mol. What is the atomic mass of the element?

a) 351.6

b) 351.0

c) 350.4

d) 352.0

e) 350.0

k) The oxidation state of vanadium in VO²⁺ is :

a) -2

b) +2

c) +1

d) -4

e) +4

l) The oxidation state of boron in B₅H₉ is:

a) +3

b) 0

c) -1/2

d) + 9/5

e) - 9/5

m) Of all the known elements in the periodic table, the atom with the largest radius is: ________________

n) As we go down a particular group in the periodic table, the effective nuclear charge (increases/decreases/stays the same) ___________________

o) Identify the neutral element that is isoelectronic with the cation Po⁴⁺ ________

p) Provide the appropriate value for the missing quantum number:
n=1, l= 0, m_l= _______?, m_s=1/2

q) Which of the following isoelectronic species is largest: Rb⁺, Kr, Br^-, Se^2-? ______________

d) How many electrons can there be with m_l = 0 when n=5?

______________

3. Write down the complete electronic configuration for each of the following ions and classify each as a noble gas ion, a pseudo-noble gas ion or an inert pair ion.

i) As^3-

ii) Cd²⁺

iii) Cs^-

iv) Sn²⁺

v) Tl³⁺

4. a) What trication has the configuration [Xe]6s²4f¹⁴5d¹⁰?

b) Is this ion paramagnetic or diamagnetic? Why or why not?

c) Classify this ion according to the type of electronic configuration.

5. The electron affinity for nitrogen is very small, whereas for oxygen and carbon it is larger. Explain this observation.

6. Complete the following table:

Molecular Lewis Dot Sketch of the Molecular Is the

Species Structure Molecule (with Shape species

lone pairs) polar?

SeF₄

SbCl₅

PF₆^-

7. Draw three valid resonance structures for fulminic acid.

Show all non-zero formal charges.

Pick the structure(s) that most accurately depict(s) the bonding in the molecule.

(Note: The sequence of atoms in the molecule is CNOH).

8. The empty molecular orbital diagram for NO^- is given below. Complete the molecular orbital diagram and then answer the questions posed below. Be sure to identify Atoms A and B and label all of the molecular orbitals in the centre of the diagram.

i) What is the bond order for NO^- in the ground state?

ii) What is the total number of p-bonds in NO^-?

iii) Classify NO^- as either paramagnetic or diamagnetic. Justify your answer.

iv) Consider NO⁺. Compare its internuclear separation to that of NO^-.

Atom A Atom B