Polyatomic Molecules Ch.5 Complete Test Bank

Chapter 5: Polyatomic Molecules

Test Bank

Type: multiple choice question

Title: Chapter 05 Question 01

1) The ‘formal charge’ is defined as?

Section reference: 5.1

a. The number of valence electrons for an atom.

b. The difference between valence electrons in the free atom and the number of atoms assigned to that atom in its Lewis structure.

c. The highest oxidation state expected in a particular group.

d. The most common oxidation state of a particular atom.

Type: fill-in-blank

Title: Chapter 05 Question 02

2) In the second period from Li to Ne, while no molecules exist which have more than eight electrons, there are some which exist with less. These molecules are described as electron ____

Section reference: 5.1

a. poor

Type: true-false

Title: Chapter 05 Question 03

3) COS adopts a structure with a central carbon atom. True or false?

a. True

Section reference: 5.1

b. False

Section reference: 5.1

Type: fill-in-blank

Title: Chapter 05 Question 04

4) When negative charges are present in a structure where formal charges can be assigned, the lowest energy structure is the one with the negative charge on the most ____________ atom.

Section reference: 5.1

a. electronegative

Type: multiple response question

Title: Chapter 05 Question 05

5) Which of the following factors affect the shape at the central atom in VSEPR theory? Please select all that apply.

Section reference: 5.2

a. The charge.

b. The σ bonded electron pairs.

c. The π bonded electron pairs.

d. The electronic contribution of the ligands.

Type: multiple choice question

Title: Chapter 05 Question 06

6) When predicting the shape of a molecule containing lone pairs, which of the following should be arranged first?

Section reference: 5.2

a. lone pairs

b. double bonds

c. single bonds

d. triple bonds

Type: multiple response question

Title: Chapter 05 Question 07

7) Which of the following geometries are predicted for molecules in which all the electron pairs are bonding in VSEPR theory? Please select all that apply.

Section reference: 5.2

a. linear

b. tetrahedral

c. square pyramidal

d. pentagonal bipyramidal

Type: true-false

Title: Chapter 05 Question 08

8) In VSEPR theory, the most important interactions that should be considered when placing bonding and lone pairs of electrons in a trigonal bipyramid occur at 90°. True or false?

a. True

Section reference: 5.2

b. False

Section reference: 5.2

Type: matching question

Title: Chapter 05 Question 09

9) Use VSEPR theory to match the molecule with its shape.

Section reference: 5.2

a. [ClF₄]^– = square planar

b. H₂S = angular

c. PH₃ = pyramidal

d. CCl₂(CH₃)₂ = tetrahedral

Type: true-false

Title: Chapter 05 Question 10

10) The shape predicted by VSEPR theory for [BrF₄]⁺ is trigonal pyramidal. True or false?

a. True

Section reference: 5.2 , Figure 5.14

b. False

Section reference: 5.2 , Figure 5.14

Type: true-false

Title: Chapter 05 Question 11

11) Using VSEPR theory, a molecule having 5 electron pairs divided between 3 bonding pairs and 2 lone pairs will be trigonal planar true-false

a. True

Section reference: 5.2 , Figure 5.17

b. False

Section reference: 5.2 , Figure 5.17

Type: true-false

Title: Chapter 05 Question 12

12) A double bond takes up less room than a single bond. true-false

a. True

Section reference: 5.2 ,

b. False

Section reference: 5.2 ,

Type: multiple choice question

Title: Chapter 05 Question 13

13) Use VSEPR theory to determine the structure of the borate anion, [BO₄]^5–.

Section reference: 5.2

a. Trigonal bipyramidal with one lone pair and four bond pairs.

b. Trigonal bipyramidal with two lone pairs and three bond pairs.

c. Tetrahedral

d. Square planar

Type: true-false

Title: Chapter 05 Question 14

14) VSEPR predicts that shape of the ion TeBr₆^2– is octahedral. True or false?

a. True

Section reference: 5.2 , Figure 5.22

b. False

Section reference: 5.2 , Figure 5.22

Type: true-false

Title: Chapter 05 Question 15

15) The linear molecule COS is non polar. True or false?

a. True

Section reference: 5.3

b. False

Section reference: 5.3

Type: fill-in-blank

Title: Chapter 05 Question 16

16) A stream of trichloromethane (chloroform) will be deflected by a positive charge because the more electronegative ____ atoms generate dipoles which do not cancel each other out.

Section reference: 5.3 , Fig. 5.24

a. chlorine

Type: fill-in-blank

Title: Chapter 05 Question 17

17) The process of an atom changing the energy and shape of its atomic orbitals to increase the opportunities for bonding with other atoms is called __________

Section reference: 5.4

a. hybridization

Type: multiple choice question

Title: Chapter 05 Question 18

18) BeMe₂ rapidly polymerizes to form a linear chain of tetrahedral Be atoms. The same process does not occur for BeBu^t₂ due to steric hindrance and the shape at Be is linear. What sort of hybridization is present in each case?

Section reference: 5.4

a. BeMe₂ is sp² hybridized and BeBu^t₂ is sp hybridized.

b. BeMe₂is sp³ hybridized and BeBu^t₂ is sp hybridized.

c. BeMe₂is sp³ hybridized and BeBu^t₂ is sp² hybridized.

d. BeMe₂is sp hybridized and BeBu^t₂ is sp³ hybridized.

Type: matching question

Title: Chapter 05 Question 19

19) For each of the atoms highlighted in bold, determine the type of hybridization present.

Section reference: 5.4

a. CH₃CH₂CCH = sp

b. C₆H₅CO₂H (benzoic acid) = sp²

c. CH₃CH₂OH = sp³

Type: true-false

Title: Chapter 05 Question 20

20) SF₆ is a hypervalent compound of sulfur which lies in the third period of the Periodic Table. Charge separation can be use to account for the exceptional valence of SF₆. True or false?

a. True

Section reference: 5.5

b. False

Section reference: 5.5

Type: true-false

Title: Chapter 05 Question 21

21) In the BeH₂ molecular orbital diagram shown below, the Be is double bonded to the H atoms. True or false?

a. True

Section reference: 5.6

b. False

Section reference: 5.6

Type: fill-in-blank

Title: Chapter 05 Question 22

22) In BeH₂, the 2σ_g orbital is closer in energy and properties to the atomic orbitals of _______

Section reference: 5.6 and LCAO theory of heteronuclear species (Chapter 4, p.209)

a. Be

Type: true-false

Title: Chapter 05 Question 23

23) The total number of electrons surrounding Xe in XeF₄ as predicted by VSEPR theory is 12. Valence bond theory would suggest that this arrangement would require d²sp³ hybridization. True or false?

a. True

Section reference: 5.6

b. False

Section reference: 5.6

Type: multiple choice question

Title: Chapter 05 Question 24

24) One way of describing the bonding in XeF₂ which avoids hypervalency for xenon is using the 3 centre 4 electron bond. Which combination of orbitals generate a non-bonding combination for the XeF₂ molecule?

Section reference: 5.7 , Figure 5.42

a. In phase combination of the two F p_z orbitals and the p_z orbital on the Xe.

b. Out of phase combination of the two F p_z orbitals and the p_z orbital on the Xe.

c. In phase combination of the two F p_z orbitals and the p_x orbital on the Xe.

d. In phase combination of the two F p_x orbitals and the p_z orbital on the Xe.

Type: multiple choice question

Title: Chapter 05 Question 25

25) The bonding in B₂H₆ is best described by which of the following statements?

Section reference: 5.7

a. 2-centre 2-electron bonds, 3-centre 2-electron bonding and 2-centre 2-electron bonding

b. 3-centre 2-electron bonding and 2-centre 2-electron bonding

c. 3-centre 4-electron bonds

d. 3-centre 2-electron bonding