EXERCISE 6-2 Lewis Structures of Molecules

Click on the correct answer


1	To answer most of the questions in this exercise, it will be necessary to draw the correct Lewis structure first. When bond angles or molecular shape are requested, it will be necessary to apply VSEPR theory to the Lewis structure. The answer desired is the value predicted by VSEPR theory. For some examples regarding bond angle, this answer will differ somewhat from the experimental value. What is the bond order (number of bonds) in N₂?
		1
		2
		3
		4
		None of the previous answers.

2	What is the bond order (number of bonds) in I₂?
		1
		2
		3
		4
		None of the previous answers.

3	What is the OCO bond angle and shape of CO₂?
		90^o, bent
		109.5^o, bent
		120^o, bent
		180^o, linear
		None of the previous answers.

4	What is the OOO bond angle and shape of O₃ (ozone)?
		90^o, bent
		109.5^o, bent
		120^o, bent
		180^o, linear
		None of the previous answers.

5	What is the HOH bond angle and shape of H₂O according to the VSEPR model?
		90^o, bent
		109.5^o, bent
		120^o, bent
		180^o, linear
		None of the previous answers.

6	What is the ClSCl bond angle and shape of SCl₂?
		90^o, bent
		109.5^o, bent
		120^o, bent
		180^o, linear
		None of the previous answers.

7	What are the bond angles and shape of CH₂O?
		90^o, 180^o, T shaped
		109.5^o, trigonal pyramid
		120^o, trigonal planar
		180^o, linear
		None of the previous answers.

8	What are the bond angles and shape of NH₃ according to the VSEPR method?
		90^o, 180^o, T shaped
		109.5^o, trigonal pyramid
		120^o, trigonal pyramid
		90^o, trigonal pyramid
		None of the previous answers.

9	What are the bond angles and shape of CH₄?
		90^o, square
		109.5^o, tetrahedral
		90^o, 120^o, trigonal pyramid
		None of the previous answers.


10	What are the bond angles and shape of CHCl₃?
		90^o, square
		109.5^o, tetrahedral
		90^o, 120^o, trigonal pyramid
		None of the previous answers.


11	What are the HOO bond angles in H₂O₂?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

12	What is the OSO bond angle in SO₂?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

13	What is the HCC bond angle in C₂H₆?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

14	What is the HCC bond angle in C₂H₄?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

15	What is the HCC bond angle in C₂H₂?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

16	What is the HCN bond angle in HCN?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

17	What is the FNN bond angle in N₂F₂?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

18	What is the ClCO bond angle in CCl₂O?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

19	What is the bond angle in N₃^-?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

20	What is the bond angle in ClO₂^-?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

21	What is the bond angle in ClO₃^-?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

22	What is the bond angle in NO₂^-?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

23	What is the bond angle in NO₃^-?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

24	What is the bond angle in CO₃^2-?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

25	What is the bond angle in NH₂^-?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

26	What is the bond angle in NH₄⁺?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

27	What is the bond angle in H₃O⁺?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

28	What is the bond angle in NO₂⁺?
		90^o
		109.5^o
		120^o
		180^o
		None of the previous answers.

29	Oxidation states give a fairly good indication of charge when the bonding is ionic in character. However, although oxidation states are used as a bookeeping method for keeping track of electrons for covalently bonded molecules, formal charges give a more accurate indication of charge for molecules. Formal charges are also a good way of choosing between structures with different sequences of bonding. The structure with the minimal formal charges is usually the one that is right. Formal charge is calculate from f.c. = valence electrons - nonbonded electrons - bonds. What is the formal charge on the central oxygen in O₃?
		0
		1
		2
		-2
		None of the previous answers.

30	What is the formal charge on the nitrogen in NO₂^-?
		0
		-3
		1
		5
		None of the previous answers.

31	What is the formal charge on the chlorine in ClO₂^-?
		-1
		0
		1
		7
		None of the previous answers

32	What is the formal charge on the end nitrogens in N₃^-?
		0
		1
		-3
		5
		None of the previous answers.

33	Nitrous oxide (laughing gas, N₂O) could have two sequences of bonding, the usually preferred symmetrical NON and the unsymmetrical NNO. Based on the formal charges for the two sequences, which sequence (and actually is) should be the right structure?
		NON
		NNO
		Can' select because the formal charges are the same.



34	Would the hydrogen in hypochlorous acid (HClO) be covalently bonded to the chlorine or the oxygen?
		chlorine
		oxygen




35	For the remaining problems, choose the chemical species that could be the model on the right. While most of models represent molecules, a few represent polyatomic ions.
		hydrogen chloride
		chlorine
		iodine monochloride
		nitrogen
		carbon monoxide

36	The model to the right could represent:
		hydrogen chloride
		chlorine
		iodine monochloride
		nitrogen
		carbon monoxide

37	The model to the right could represent:
		hydrogen cyanide
		ozone
		nitrite
		water
		carbon dioxide

38	The model to the right could represent:
		hydrogen cyanide
		ozone
		nitrite
		water
		carbon disulfide

39	The model to the right could represent:
		hydrogen cyanide
		ozone
		nitrite
		water
		carbon dioxide

40	The model to the right could represent one of the resonance structures of:
		hydrogen cyanide
		ozone
		nitrite
		water
		carbon dioxide

41	The model to the right could represent:
		acetylene (C₂H₂)
		formaldehyde (CH₂O)
		nitrate
		hydrogen peroxide (H₂O₂)
		ammonia

42	The model to the right could represent:
		acetylene (C₂H₂)
		formaldehyde (CH₂O)
		nitrate
		hydrogen peroxide (H₂O₂)
		ammonia

43	The model to the right could represent one of the resonance structures of:
		acetylene (C₂H₂)
		formaldehyde (CH₂O)
		nitrate
		hydrogen peroxide (H₂O₂)
		ammonia

44	The model to the right could represent:
		carbon tetrachloride (CCl₄)
		methane (CH₄)
		chlorate
		thiosulfate
		None of the previous answers.

45	The model to the right could represent:
		carbonic acid
		oxalic acid
		acetic acid
		chromic acid
		None of the previous answers.