OCHEM HW1 2020 - Blank PDF

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OCHEM HW1 2020 - Blank copy for practice...

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Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

This is the Gradescope portion of your weekly homework. For the Gradescope portion of both weekly homework and midterm exams, you will be required to hand write answers to all questions and then scan and upload them to the appropriate grade scope assignment. Half of this assignment is graded based on completion, while the other half of possible points will be assigned based on the accuracy of a problem(s) that we will randomly chose to grade for correctness. For this assignment, you should solve the problems on a separate sheet, and only upload clearly labeled answers that clearly corresponding the given problem number. Failure to clearly indicate the correct answer, providing multiple answers, forgetting to include required information, or mislabeling of answers will result in the loss of points, so please, do this correctly! You must include your name, UT EID, and signature on each page you upload. An example of showing acceptable formatting of a Gradescope submission is shown below. ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

If you make a mistake, clearly erase/scribble it out and note what you want to be graded.

Feel free to box answers/ add lines to clearly separate your answers

1

Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

Name: _______________________ EID:_________________________ Signature: ____________________

1. (1 pt) What is the most important question in chemistry?

2. (4 pts) Redraw the molecules below. Then, draw the indicate the direction of the dipole of the bond listed. A. C-Br

C. O-H H

H C

H

symbol next to your structure to

Br

H

O

H

C

N

H

H

H

B. C-O

D. C-N

H

H C

H

C

O

H

H

H

H

H

3. (5 pts) Some of the molecules shown below have formal charges. Redraw all of the molecules below, and for those that have formal charges, write the correct formal charge next to the appropriate atom. IN ADDITION, SOME OF THE ATOMS ON THESE MOLECULES NEED LONE PAIRS ADDED. ADD ALL VALENCE LONE PAIRS OF ELECTRONS WHERE APPROPRIATE.

H

H

H

H

C

N

C

H

H

H

H B H

H

H

C

C

H

H

H

H

F

2

F

H

C

C

F

H

H O

O H

H

O C OH

H

Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

Name: _______________________ EID:_________________________ Signature: ____________________ 4. (9 pts) For the following molecular formulas, draw complete Lewis line structures in which all atoms (even H atoms) are drawn, lines are used as bonds, and all lone pairs and formal charges are drawn. A. (CH3)3CCH2CH2CO2H

B. H2CCHCH2CHCH2

C. CH3OCH2CH2NH3

D. (CH3)2CCHCN

E. HCON(CH3)2

F.

CH3CH2CH3

H. CH2CHCHCH2 G. (CH3)2CHCH3

I. CH3NO2

3

Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

Name: _______________________ EID:_________________________ Signature: ____________________ 5. (8 pts) The following molecules are best represented as the hybrid of contributing structures. First redraw the structure on the left. Next, draw the second important contributing structure to the right, including all lone pairs and formal charges. For the structure you copied on the left, use arrows to indicate the movement of electrons to give the structure you drew on the right. Finally, if one of the two contributing structures makes a dominant (major) contribution to the resonance hybrid, draw a circle around the dominant (major) contributor. You might want to read these directions again to make sure you know what we want. A. H H

O C

C H

O

H

O

B.

H

C

C

C

H

H

H

C.

H C

N

N

H

H

D.

H

C H

C C

H

H

4

Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

Name: _______________________ EID:_________________________ Signature: ____________________ 6. (6 pts) The following molecules are best represented as the hybrid of three contributing structures. First redraw the structure on the left, then draw the second and third important contributing structures, including all lone pairs and formal charges. Use arrows to indicate the movement of electrons to show how the first structure can form the second, and how the second structure can form the third strucure. There is no need to draw any circles around any of these contributing strucures. You might want to read these directions again to make sure you know what we want. A. O O

C O

B. H

O C

H

N O

C.

H

H

O

C

C

H

O

N

H

H

O

Frog diketone (not a problem, just here to make you smile)

5

Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

Name: _______________________ EID:_________________________ Signature: ____________________ 7. First redraw the following molecules, then for each: 1) Use the sign to indicate the direction of the bond dipole in all of the polar bonds. 2) Circle all molecules that have a measurable molecular dipole moment. 3) For the molecules you circled, to the best of your artistic ability, use an additional sign to indicate the direction of the molecular dipole moment on the left side of the molecule. (7 pts)

H

H C

H

H

H H

C

F

F

F

F

O

F

F

C

F

C

H

F

H

F

H

C

C F

H

O

O

H

H

H H

N H

8. (4 pts) Redraw the following molecules, then use the dipole moment symbol to show the direction of the molecular dipole moment in all molecules that have an overall molecular dipole.

H

Cl

Cl

C

H C H

H Cl Cl

Cl

Cl

H C

H

C

C

O

O

O For the molecule above list the molecular dipole for the conformation shown.

C H

H

6

Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

Name: _______________________ EID:_________________________ Signature: ____________________

9. (11 pts) Describe each bond indicated with an arrow as the overlap of orbitals. For example, an answer might be

σ Csp -Csp . 3

3

C.

H

B.

C H

C

D.

C H

A.

E.

H F.

H.

G.

H

I.

H

H C H

C

H

C

C

H

O

K. J.

7

Homework 1: Gradescope

Iverson CH320M/328M

Due Friday, Sept. 4

Name: _______________________ EID:_________________________ Signature: ____________________ 10. (8 pts) Describe each bond indicated with an arrow as the overlap of orbitals. For example, an answer might be

σ Csp -Csp 3

3

A.

H D.

H H

C

H H

O N

C C

C

C

E.

H C

C Cl

H

C C

C

N F.

H B.

H

H

C C

C

G.

C C.

C

H

C

Valium

H

8

H H....