Homework Assignment 2012 - 1, 2, 5, 7, 9, 10 - Survey Of Organic Chem PDF

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Download Homework Assignment 2012 - 1, 2, 5, 7, 9, 10 - Survey Of Organic Chem PDF

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Homework 1 Solutions 1. Which compound is not a constitutional isomer of the others?

I II III IV All of the above are isomers of each other.

2. How many sigma 1s-2sp3 bonds are there in ethane? 3 6 7 1 5 3. Which of the following is the Lewis structure for CH3CH2O2H?

4. In which of these cases does the central atom have a zero formal charge?

HFH

5. In which structure(s) below does nitrogen have a formal charge of +1?

I and V V I II and IV III and V

6. Which of the following species is/are not a resonance form(s) of the anionic species in the box?

I and IV I II and III I and III III and IV

7. When the 1s orbitals of two hydrogen atoms combine to form a hydrogen molecule, how many molecular orbitals are formed? 2 5 4 1 3

8. How many s-sp3 bonds are there in the following substance?

3 16 8 12 13

9. Cis-trans isomerism is possible only in the case of: BrCH=CHBr Br2C=CBr2 Br2C=CHBr CH2=CBr2

CH2=CHBr

10. Which compound has the shortest carbon-carbon bond(s)? All carbon-carbon bonds are the same length. CH3CH3 CH3CH2CH3 CH2=CH2

HC

CH

11. What is the hybridization of the C indicated with the arrow?

s p sp3 sp2 sp

12.The bond angles for the bold-faced

C in CH3CH2CH2+ would be expected to be approximately:

105° 120° 90° 109° 60° 13. What is the approximate hybridization state of the oxygen molecule in ethanol, C2H5OH? d2sp3 p3 sp3 sp sp2

14.Identify the atomic orbitals in the C-N sigma bond in the following oxime:

(2sp, 1s) (2sp2, 2sp3) (2sp, 2sp) (2sp2, 2sp2) (2sp3, 2sp3)

15.Which of the following would have a trigonal planar (or triangular) structure?

I, II, and IV II and IV IV II, IV, and V All of these

16.Which of these substances contain both covalent and ionic bonds? H2S CH4 NH4Cl H2O2 HCN

17. What is the geometry of the N in the following molecule?

tetrahedral trigonal planar trigonal pyramidal linear bent

18. The following electron configuration represents _______

the sp3 hybridized state of nitrogen. the ground state of carbon. an excited state of carbon. the ground state of boron. the sp3 hybridized state of carbon.

19.Expansion of the valence shell to accommodate more than eight electrons is possible with: Nitrogen Sulfur Beryllium Fluorine Carbon

20. Which of the following species exhibits resonance stabilization? None of the species above exhibit resonance. O3 CO2 CCl4 H2SO4

Homework 2 Solutions 1. Consider the equilibrium Which are the Bronsted-Lowry bases? PO43- and OHPO43- and H2O H2O and OHH2O and HPO42PO43- and HPO42-

2. This species is a carbon-based Lewis acid: ·CH3 CH4 HCCl3 :CH3CH3+

3. The reaction between which combination of substances below cannot be classified as a Bronsted-Lowry acid-base reaction? CH3Li + C2H5OH H2SO4 + CH3CO2Na BF3 + NH3 H3O+ + CH3NHtwo of the above

4. Hydrogen atom(s) from which position(s) is (are) most likely to be abstracted when the following substance is treated with a strong base (i.e. what is the most acidic H)?

1 Hydrogens from all of the positions are equally likely to be abstracted by NaH. 1, 5, 6 3, 4, 7, 8, 9, 10 1, 2

5. The compounds ethane, ethene, and ethyne exhibit this order of increasing acidity: Ethene < ethane < ethyne Ethene < ethyne < ethane Ethane < ethyne < ethene Ethyne < ethene < ethane Ethane < ethene < ethyne

6. Which molecule has a zero dipole moment? CH3Cl CH2Cl2 CHCl3 CCl4 None of these

7. Of the following organic solvents which one does not have a zero dipole moment (i.e. contains a polar covalent bond)? Pentane Cyclohexane Diethyl ether Cyclopentane None of these

8. Which molecule has a zero dipole moment? CO2 CH4 CH3CH3

All of these

Which is the most polar bond? A) C-H B) O-O C) N-H D) O-H (answer) E) N-N

9.

10. What is the conjugate acid of CH3NH2? A) CH3NH– B) NH4+ C) CH3NH3+ (answer) D) NH2– E) CH3NH2

11.

Which of the following compounds is the strongest acid? (A) CH3COOH (B) FCH2COOH (answer) (C) ClCH2COOH (D) BrCH2COOH

12.

Which of the following terms describes the reactivity of boron tribromide, BBr3? (A) Bronsted-Lowry acid and Lewis acid (B) Bronsted-Lowry base and Lewis base (C) Lewis acid and not a Bro onsted-Lowry acid (answer) (D) Lewis base and not a Bronsted-Lowry base

13.

What is the value of the equilibrium constant, Keq, for the following reaction?

(A) 109 (B) 10-9 (answer) (C) 9 (D) 1/9

14.

Which species is the conjugate acid in the following acid-base reaction?

(A) 1 (B) 2 (C) 3 (D) 4 (answer) 15.

Which of the following compounds is the strongest acid? (A) CH3OCH3 (B) CH3CH2OH (C) CH3CHO (D) CH3CO2H (answer)

16. Which of the following anions is the strongest base?

(A) CH3COO(B) HO(C) NH2- (answer) (D) Cl17.

Which of the following is present in the highest concentration upon dissolution of H2SO4 in water? (A) H2SO4 (B) H+

(C) H3O+ (answer) (D) HO18. Which species is the conjugate acid in the following acid-base reaction?

(A) 1 (B) 2 (C) 3 (D) 4 (answer) 19. Which of the following concepts can be used to rationalize the observation that acetic acid is a stronger acid than methanol?

(A) electronegativity (B) resonance (answer) (C) valence shell electron pair repulsion theory (D) Pauli exclusion principle 20.

Which species is the conjugate base in the following acid-base reaction?

(A) 1 (B) 2 (C) 3 (answer) (D) 4

CHEM 1315 HW 5-Due Noon, Thursday, September 27, 2012

Homework 5 Questions You MUST answer on a SCANTRON card which will be distributed in lecture or are available outside Molecular Science and Engineering 2222L. You must bubble in your 9 digit GTid number to receive credit for this assignment. 1. Which of the following statements are correct concerning delocalized electrons? A) Electrons do not belong to a single atom. B) Electrons are not confined to a bond between two atoms C) Electrons are shared by three or more atoms. D) All of the above. (correct) 2. Which of the following pairs are resonance structures?

A. I

B. II

C. III (correct)

D. IV

E. V.

3. Which of the following is not a resonance structure of the species shown?

A. I C. III

B. II D. IV (correct)

4. What is the major product of the following reaction?

H

H2O, H2SO4, Hg ++

?

O

OH

H

O

A.

B. (correct)

C.

D.

5. What is the major product of the following reaction? H2O, H2SO4, Hg++

?

H O

OH

OH

O

A. (correct)

B.

C.

6. What reagents would be used to perform the following transformation?

A. H2, Pt, Quinoline, calcium carbonate C. MeOH, H2SO4

B. H2, Pd (correct) D. H2O, H2

7. What reagents would be used to perform the following transformation?

D.

? Ph

Ph

A. H2, Pt, Quinoline, calcium carbonate C. MeOH, H2SO4

B. H2, Pd (correct) D. H2O, H2

8. What is the major product of the following sequence of reactions? 1. NaNH2 2. MeI

?

3. H2, Pt

I

A. (correct)

B.

C.

9. What is the major product of the following reaction?

A. (correct)

B.

C.

D.

10. What is the major product of the following sequence of reactions?

D.

A.

B. (correct)

C.

D....