Blog

Testing Along with Luke’s strange behavior, he also begins having seizures. Luke’s parents are extremely concerned and call an ambulance and Luke is transport to the hospital.  At the hospital, samples of blood were taken and sent to various labs for testing. After he was sedated, Luke had a lumbar puncture procedure to remove a sample of cerebral spinal fluid (CSF), which was sent for culture and also for direct observation with a phase contrast microscope. While waiting for the results of his spinal tap, Luke’s doctors start him on antibiotics.  Question: With the information gathered at the hospital, Luke most likely has which of the following?

Sucrose (shown below) is a sugar produced mainly by plants and is refined to become table sugar. Answer the questions below about the structure of sucrose. Which two (2) chair structures below represent the chair conformations of the six-membered ring of sucrose? Enter your choices in alphabetical order: [chair1] and [chair2]. Which of the chair structures represents the enantiomer of the six-membered ring of sucrose? [enant] What is the absolute configuration (R or S) of the chiral center indicated with an asterisk (*)? [RSconfig]

When ammonium nitrate (NH4NO3) is dissolved in water, the temperature of the NH4NO3 solution is lowered (cooled). Is it a? (1 point)

Which of the following material is a heterogeneous mixture?

“Melting of ice” is a?

Mannose is a naturally occurring sugar that is important to human metabolism. Mannose can exist in an open chain form (D‑mannose) or can cyclize to form a cyclic structure (β-D‑mannopyranose). Answer the questions below about D‑mannose and β-D‑mannopyranose. Which of the Fischer projections (A-F) below represent D‑mannose? [Fischer] Which of the chair conformations (T-Z) below represent the MOST stable conformation of β-D‑mannopyranose? [chair1] Which of the chair conformations (T-Z) below represent the LEAST stable conformation of β-D‑mannopyranose? [chair2] How many total possible stereoisomers are there for β-D‑mannopyranose (including the one drawn)? [stereopyr] How many diastereomers are possible for D-mannose? [diasman] The anomeric center of a cyclic sugar is the newly formed chiral center resulting from the cyclization reaction. Which of the carbon atoms labeled 1-6 above is the anomeric center? [anomeric] Identify ONE chair conformation (T-Z) that represents the enantiomer of β-D‑mannopyranose. [enantiomer] What is the relationship between the Fischer projections labeled D and E? [relationship]

Consider the hydrobromination reaction shown below and answer the questions that follow. In this reaction, a “MAJOR PRODUCT” is formed, i.e. a product that is formed in preference to the other. Assuming that the major product is derived from the most stable possible carbocation intermediate, which of the following molecules (A-F) would be the MAJOR product? [major] A “MINOR PRODUCT” is also possible in this reaction, i.e. any possible product that is not the major product. Which of the following molecules (A-F) would be the MINOR product? [minor] Considering only the major product, how many stereoisomers are possible for this molecule? [stereomajor] Considering only the minor product, how many stereoisomers are possible for this molecule? [stereominor]

Rank the following carbocations in order of increasing stability. least stable [1] < [2] < [3] < [4] most stable

How many molecules are in 4.5 moles of CCl4? (2 point) (Avagadros’s number is: 6.022 X 1023)

Please select the section which represents the following description: Township 4S, Range 6E of the 4th Principal Meridian