H₂N- NO2 1. To separate an organic base, 3-nitroaniline, from neutral acetophenone, a solution of hydrochloric acid was added. The 3-nitroaniline forms a hydrochloride salt, and you are able to extract the compound into your aqueous layer, while the acetophenone remains in the organic layer. What would you add to the aqueous layer to recover the 3-nitroaniline? (3 points) 2. Suppose you isolated the two compounds above but failed to label which came from the aqueous layer and which came from the organic layer. How could IR help you decide which was which? (E.g., the acetophenone would show a peak around _representing, but the 3-nitroaniline would not.) Provide 3 differences expected. (6 points) benzoic acid 3000 1 2000 NAVENUMBER- τη dimethoxybenzene 1500 1000 500 9000 2000 J000 LOOD HAVEHUIZERI

In a 0.01 M solution of 1,4-butanedicarboxylic acid, HOOCCH 2CH 2COOH ( K a1 = 2.9 × 10 –5, K a2 = 5.3 × 10 –6), which species is present in the lowest concentration? -OOCCH2CH2COO-(aq) H2O (l) HOOCCH2CH2COO- (aq) H3O+(aq) HOOCCH2CH2COOH (aq)

In acylation reactions of alcohols with acyl chlorides, external amine such as triethylamine (Et,N) or pyridine are used. Which statement about these additives is incorrect They scavenge HCI O They act as a Lewis base They can be used as a solvent They deprotonate the alcohol to form alkoxide

Equilibrium of methyl orangea) Give a balanced reaction equation for the reaction of methyl orange with 6M HCl b) Give a balanced reaction equation for the reaction of methyl orange with 6M NaOHc) Use Le Chatelier’s Principle to explain the color change when acid or base is added to methyl Orange. Reaction: HMO = H^+ +MO^-

The following compound is derived from one of the twenty mammaliam "amino acids". It is the ethyl ester of arginine . If you offer a proton (H+) to this molecule, what is the expected conjugate acid that is formed. Draw its structure, thank you!

Acid-Base Equilibria Many factors contribute to the acidity of organic compounds. Electronegativity, resonance, induction, hybridization, aromaticity, and atomic size, all play a role. In the following comparisons, you are asked to identify the factor(s) that would be most important to analyze when predicting relative acidity, and then to predict the trend in acidity and pKa values. For each of the following pairs of compounds answer the following two multiple-choice questions. 1. What factor(s) are the most important to consider when predicting the relative acidity of the two compounds? a. Electronegativity of the atom possessing the hydrogen. b. Resonance stabilization of the anionic conjugate base. c. Inductive stabilization of the anionic conjugate base. d. Hybridization of the atom possessing the hydrogen. e. The atomic size of the atom possessing the hydrogen.

Write an equation for the acid-base reaction between 2,4-pentanedione and sodium ethoxide and calculate its equilibrium constant, Keq. The pKa of 2,4-pentanedione is 9; that of ethanol is 15.9.

Low-molecular-weight dicarboxylic acids normally exhibit two different pKa values. Ionization of the first carboxyl group is easier than the second. This effect diminishes with molecular size, and for adipic acid and longer chain dicarboxylic acids, the two acid ionization constants differ by about one pK unit. Why do the two pKa values differ more for the shorter chain dicarboxylic acids than for the longer chain dicarboxylic acids?

If a solid mixture of the three aromatic compounds shown below is placed in 3 M HCl, which is likely to dissolve?

Another way to express acid strength is by using pk b:pK a =−logK a Another way to express base strength is by using pK b pK b =−logK b A new potential heart medicine, code-named X-281, is being tested by a pharmaceutical company, Pharma-pill. As a research technician at Pharma-pill, you are told that X-281 is a monoprotic weak acid, but because of security concerns, the actual chemical formula must remain top secret. The company is interested in the drug's K a value because only the dissociated form of the chemical is active in preventing cholesterol buildup in arteries.To find the pK a of X-281, you prepare a 0.079 M M test solution of X-281 at 25.0 ∘ C The pH of the solution is determined to be 3.00. What is the pK a of X-281?