Chem 121                                Sample Exam 3                        Name __________________

                                                                                                Dr. Drisko, Instructor

All work must be clearly shown where appropriate. Some data and equations you may or may not need: E=(hc)/l; h= 6.626 x 10^-34 joule sec; c= 3 x 10⁸ meters/sec; n = c/l

Schrodinger

1. measured the charge to mass ratio of cathode ray particles
2. measured the charge on the electron
3. proposed the nuclear model of the atom
4. suggested the energy of the electron is quantized
5. proposed the theory that we call quantum mechanics

Which of the following colors in the visible spectrum has the highest energy?

1. blue
2. yellow
3. green
4. orange
5. red

1. s
2. p
3. d
4. f
5. g

In the 3d subshell the maximum possible number of electrons is

1. 2
2. 6
3. 10
4. 14
5. 18

In the second shell (n=2) the maximum possible number of electrons is

1. 2
2. 4
3. 6
4. 8
5. 10

Which quantum number is shared by all the electrons in the shell?

1. principal (n)
2. angular momentum (l)

0. magnetic (m or m _l) 

3. spin (s or m_s)
4. none of these

The possible m values for l = 1 are

1. 0
2. -1, 0,+1
3. 0,1
4. s,p,d,f
5. none of these

The maximum number of electrons in any orbital is

1. 2
2. 6
3. 10
4. 14 
5. there is no maximum

The ground state electron configuration of neodynium, atomic number 60 is

1. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f⁵
2. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f⁴
3. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s¹4f⁵
4. 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶4f⁶

Which statement is true about the ground state of the Co⁺².ion?

1. The number of unpaired electrons is zero and the Co⁺² ion is paramagnetic
2. The number of unpaired electrons is zero and the Co⁺² ion is not paramagnetic
3. The number of unpaired electrons is three and the Co⁺² ion is not paramagnetic
4. The number of unpaired electrons is three and the Co⁺² ion is paramagnetic
5. The number of unpaired electrons is one  and the Co⁺² ion is paramagnetic

. The Core for I is

1. [Ar]
2. [Br]
3. [Kr]
4. [Te]
5. [Xe}

Choose the electron configuration that corresponds to an excited state:

1. [Ar]3d³4s²
2. [Kr]5s¹
3. [Ar]3d⁵4s¹
4. [Ne]3s¹3p⁶
5. [Xe] 4f¹⁴5d¹⁰6s²

The general trend in atomic size from left to right across a period is

1. increasing size
2. decreasing size
3. size is constant
4. size varies in a random way

The general trend is size in going down a family from top to bottom is

5. increasing size
6. decreasing size
7. size is constant
8. size varies in a random way

. Se is a (an)

1. s block element
2. p block element
3. d block element
4. f block element
5. g block element

Vanadium is a (an)

6. s block element
7. p block element
8. d block element
9. f block element
10. g block element

Which of the following is a metal

1. O
2. N
3. Br
4. Ca
5. Ar

The name commonly associated with the IA family (or group 1) is

1. halogen family
2. noble gas family
3. alkaline earth family
4. alkali metals
5. none of these

 

 

1.	Carbon uses ______ hybrid orbitals in ClCN.
A.	sp

 

B.

sp2

 

C.

sp3

 

D.

sp3d

 

E.	sp3d2
2.	Valence bond theory predicts that iodine will use _____ hybrid orbitals in ICl2-.

 

A.

sp2

 

B.

sp3

 

C.

sp3d

 

D.

sp3d2

 

E.	none of these choices is correct

 

3.	(4 pts) A molecule with the formula AX4 uses _________ to form its bonds.

 

A.	sp hybrid orbitals

 

B.	sp2 hybrid orbitals

 

C.	sp3 hybrid orbitals

 

D.	sp3d hybrid orbitals

 

E.	sp3d2 hybrid orbitals
4.	Which one of the following statements about orbital hybridization is incorrect?

 

A.	The carbon atom in CH4 is sp3 hybridized.

 

B.	The carbon atom in CO2 is sp hybridized.

 

C.	The nitrogen atom in NH3 is sp2 hybridized.

 

D.	sp2 hybrid orbitals are coplanar, and at 120° to each other.

 

E.	sp hybrid orbitals lie at 180° to each other.

 

5.	(4 pts) A molecule with the formula AX3E uses _________ to form its bonds.

 

A.	s and p atomic orbitals

 

B.	sp3 hybrid orbitals

 

C.	sp2 hybrid orbitals

 

D.	sp hybrid orbitals

 

E.	sp3d2 hybrid orbitals

 

6.	According to valence bond theory, the triple bond in ethyne (acetylene, C2H2) consists of

 

A.	three σ bonds and no π bonds.

 

B.	two σ bonds and one π bond.

 

C.	one σ bond and two π bonds.

 

D.	no σ bonds and three π bonds.

 

E.	none of these choices is correct
7.	Which of the following statements relating to molecular orbital (MO) theory is incorrect?

 

A.	Combination of two atomic orbitals produces one bonding and one antibonding MO.

 

B.	A bonding MO is lower in energy than the two atomic orbitals from which it is formed.

 

C.	Combination of two 2p orbitals may result in either σ or π MOs.

 

D.	A species with a bond order of zero will not be stable.

 

E.	In a stable molecule having an even number of electrons, all electrons must be paired.
8.	In the context of molecular orbital (MO) theory, explain how atomic p orbitals can give rise to: a. a σ MO b. a π MO

 

  rt II

1.a.   If n =6, what values are possible for l?

b.If l = 5, what values are possible for m_l?

c.What is the subshell label (s,p,d,f, etc) if n = 6, l = 2, and m_l= -1?

d.Give one set of 4 possible quantum numbers for an electron in the 6d orbital.

2.A popular AM radio station broadcasts at  a frequency of 650 kHz.  What is the wavelength in meters of the electromagnetic radiation emitted by this station?

3.a.   Sketch the orbital energy diagram (vertical orientation) including electrons for the S atom in its ground state.

2. Write the complete electron configuration for the S 

4. Write the abbreviated orbital diagram (horizontal orientation) for the ground state of

1. Al

2. K

3. Sn

4. V

5.Write abbreviated electron configurations for each of the following and tell how many unpaired electrons each has

1. boron

2. fluorine

3. silicon

6. How many unpaired electrons are in the ground state of each species?

1. a scandium (Sc) atom

2. a Sc³⁺ ion

3. a titanium (Ti) atom

4. a Ti²⁺ ion

7. Arrange each group of atoms in order of decreasing radius:

1. Br, Cl, Se

2. Al, Mg, Si

8. Which is larger in each part?

1. H⁺ or H^- ?

2. H^- or H?

3. Fe²⁺ or Fe³⁺ ?

9. Which is (are) isoelectronic with Kr?

1. Se^2-

b.   Sr²⁺

c.   Zn²⁺

10. Which member of each pair has the higher value for first ionization energy?

1. Mg or Na

2. K or Na

3. Ar or Cl