QUESTION 2 Which of the following statements about resonance structures is true? The placement of nonbonded electrons is the same. The placement of atoms is different. The placement of 77 bonds is different. The placement of a bonds is different. QUESTION 3 Rank the following compounds in order of increasing stability, putting the least stable first. 0000 ||| > | > || ||| < | < || ||| < || < | |<< III || III

Shown below are the free radicals formed from 1,2- dimethylcyclopentane. I a. II || > | > ||| O b. O c. O d. II > | > | I>ll> ||| >> || Arrange in terms of decreasing stability. III

REPRESENTATIONS OF ORGANIC MOLECULES Identifying isomers and resonance structures Determine the relationship between Structure A and Structure B in each row of the table. Structure A Structure B Relationship H. o isomers H. H H -H H-C- C-O -H- O resonance structures H H. H H Н—С—Н o neither H o isomers H :0: :0-H H. H H- C-C C-H H-C=C C=C-H O resonance structures H. H. H o neither o isomers :o: H H. H- O resonance structures H H H. H o neither 72°F DELL :ö: II

JA H;° of H2O(1) is -285.8 kJ/mol. calculate A H;° of MgO. The relevant reactions for these two heats of formation are: H2(g) + ½ O2(g) H20(1) and Mg(s) + ½ O2(g) - MgO(s) > -141.3 kj/mol a) -306.6 kj/mol b) -447.9 kj/mol c) d) -592.4 kj/mol 141.3 kj/mol f) Not even information given

MODIFIED TRUE OR FALSE. ite the letter T or F inside each box after deciding which statement is true or false. Then on the: box, write the letter of your choice based on the given instructions. A if both statements are true B if the 1st statement is false and the 2nd statement is true C if the 1st statement is true and the 2nd statement is false D if both statements are false Compounds formed from their elements in exothermic reaction have negative AH; lonic compounds usually have more negative enthalpies of formation. Thermodynamics can tell us the direction and extent of a reaction but tells nothing about the speed of a reaction. Majority of spontaneous reactions are exothermic especially in irreversible reactions. Enthalpy provides a quantitative measure of how much energy is spread out when something happens. Entropy is associated with the second law of thermodynamics.

Which of the following is a resonance structure of the compound below? 0=0 H CH₂CH3 || III ON H₂C H₂C 11 Нас-с CHOH CH3 HẠCHO CH E ||| :0 HC CH3 IV

b. H,O CH3CH2CH=CH2 acid Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. The single bond is active by default.

3. Use the symbols 6* and & to show the direction of the polarity of the indicated bond in H,C-OH. Use the symbois 6 and 6 to show the direction of the polarity of the indicated bond in each of the following compounds: (a) HO-H (b) F- Br (c) H,C- NH, (d) H,C-CI (e) HO - Br (1) H,C-Li (8) 1- CI (h) H,N - OH

Draw the structural formula of cycloheptanecarboxylic acid. Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. The single bond is active by default. EXP CONT H N S CI Marvin JS Br by ChemAxon P O ® 0 \'z 1 •'