C341/ Chapter 1: General Chemistry Review sheet
1. For the condensed formula below, perform the following functions: a. Draw the correct Lewis structures and fill in the correct number of lone pairs and/or double bonds. b. Determine the molecular shape around each non‐hydrogen atom. (tetrahedral, bent, etc.) c. Determine ideal bond angles and identify any distortions from ideal bond angles. d. Provide an orbital hybridization description for any atom and be able to describe the bonds in terms of overlapping atomic orbitals (sigma, pi, etc.). In what types of orbitals do lone pairs reside? f. Which molecules are polar? Which molecules would be soluble in polar solvents? Draw in the δ+ and δ‐ signs for the polar bonds. g. Finally, draw the correct lines structures for these compounds and identify the functional groups in each. CH3NHCH3 CH3CONHCH2CH3 (CH3)CHC(CH3)2 CH3COCH3 CH2CHCOCH3 CHCCH2CH2COOCH3 2. Identifying conjugation. The first step to being able to draw resonance structures is to identify conjugated atoms. On the structure of capsaicin below circle all of the conjugated atoms. Capsaicin is the active component to chili peppers. The spicy flavor of capsaicin comes from its interaction with olfactory and other receptors. The strength of the interaction is controlled by a variety of factors, including electrostatic interactions, which might arise from uneven electron distribution in the capsaicin molecule. Resonance influences this electron distribution. Page 1 of 4
C341/ Chapter 1: General Chemistry Review sheet
3. Practicing resonance. The protein content of a food sample is estimated by determining its nitrogen content. The apparent protein content of some wheat gluten was boosted by the addition of melamine. While melamine is rich in nitrogen, it causes kidney failure if the amount is high enough. Polymerization of melamine with formaldehyde (H2C=O) gives melamine resin, a tough plastic used in kitchen countertops and bowls. Using curved arrows, provide two more resonance structures for melamine. 4. Utilize arrows properly to show the formation of all other resonance structures if they exist. Circle the most stable resonance structure for each below. a. b. c. d. e. f. Page 2 of 4
C341/ Chapter 1: General Chemistry Review sheet
5. Determine the functional groups below. Explain why the first two compounds which have the same molecular formula, C4H10O, have such different boiling points. How would you expect 2‐butanone boiling point to compare to these relatively? Discuss their order of solubility in water. O
HO
O
bp= 108 oC 34.6 oC ?? 6. Draw line drawings for all isomers of molecular formula C4H10O. Identify the functional groups and discuss the carbons as primary, secondary and tertiary. If you drew an alcohol, is it a 1o, 2o, or 3o? 7. Write the Lewis structures and condensed structural formulas for all isomers of molecular formula C4H8O. Identify the functional groups and discuss the carbons as primary, secondary and tertiary. 8. Fill in the lone pairs on all heteroatoms in each compound and assign correct formal charges. Page 3 of 4
C341/ Chapter 1: General Chemistry Review sheet
9. Identify as many functional groups as possible and then list the intermolecular forces (LF, DD, HBA, HBD) found in each of the following molecules. What is the five carbon rule? Predict whether the following molecules would be soluble in water. HO
O
O
O
Aspirin Melatonin Vitamin C Vitamin E Vitamin B6 O
O
N
H
O
N
H
OH
Vitamin D Dimitone – antihypertensive medication N
O
N
OH
NH2
Sabril – seizure medication Cl
O
Claritin – treats seasonal allergies
Page 4 of 4
O