15. Analytical Techniques:IR, NMR, Mass Spect

In the context of analytical techniques, what is the primary purpose of using a flask in an experiment?

What is the primary purpose of using analytical techniques in organic chemistry?

What was the primary purpose of the Miller-Urey experiment in the context of organic chemistry?

Which of the following best describes the purpose of preparatory reactions in analytical techniques?

In the context of analytical techniques, what is the primary purpose of a positive control?

What was the primary purpose of the Miller-Urey experiment in the context of analytical techniques in organic chemistry?

What is the primary purpose of the four postulates in analytical techniques?

What is the primary purpose of using a streak plate in analytical techniques?

Draw the expected results of a DEPT sequence for the molecules shown.

(b)

A student obtained two products from the reaction of 1,3-cyclohexadiene with Br₂ (disregarding stereoisomers). His lab partner was surprised when he obtained only one product from the reaction of 1,3-cyclohexadiene with HBr (disregarding stereoisomers). Account for these results.

Why are polyacrylamide gels preferred over agarose gels for analyzing protein fractions?

Draw the expected results of a DEPT sequence for the molecules shown.

(a)

With information from the ¹H NMR and the ¹³C DEPT spectra, structure elucidation becomes even easier. Provide the structure that corresponds to the following data. [The identity of the carbons comes from the DEPT experiment.]

C₆H₁₁BrO₂

IR: 1745 cm ⁻¹

¹H NMR: δ 1.25 (t, 3H), 2.18 (quint, 2H), 2.58 (t, 2H), 3.46 (t, 2H), 4.15 (q, 2H)

¹³C NMR: δ 14.2 (CH₃) , 27.8 (CH₂) , 32.5 (CH₂) , 32.6 (CH₂) , 60.5 (CH₂) , 172.4 (C)