IR and NMR spectroscopy

An unknown molecule has a molecular formula C₅H₁₀O. Which of these four molecules corresponds to the IR spectrum above?

• 
• 
• 
• 

Tags

NGSS.HS-LS1-6

An unknown molecule has a molecular formula C₆H₁₂O. Which of these four molecules corresponds to the IR spectrum above?

• 
• 
• 
• 

An unknown molecule has a molecular formula C₆H₁₄O. Which of these four molecules corresponds to the IR spectrum above?

• 
• 
• 
• 

An unknown molecule with a formula C₄H₈O₂ smells like vomit. Which of these molecules corresponds to the IR spectrum shown above?

• 
• 
• 
• 

Tags

NGSS.HS-PS4-3

A compound has a formula C₅H₁₀O. The NMR spectrum is shown above. The compound shows a sharp peak at around 1750cm^-1 in the IR spectrum. Identify the compound.

• pentanal

• 2-pentanone

• 3-pentanone

• 2-pentanol

• A

• B

• C

• D

An ester has an NMR spectrum as shown above. Which of these could be the ester?

• 
• 
• 
• 

The NMR spectrum for an isomer of C₄H₉Br is shown above. Which peak can be used to show that the isomer is not a primary alkyl halide?

• A

• B

• C

• D

Which of the following statements regarding IR spectroscopy is wrong?

• Infrared spectra record the transmission of IR radiation through organic molecules

• Molecular vibration is due to periodic motions of atoms in molecules such as bond stretching

• Infrared spectra give information about functional groups in molecules

• The molecular formula of molecules can be deduced from infrared spectra

Tags

NGSS.HS-PS4-3

Tetramethylsilane (TMS) is used as a reference in NMR spectroscopy due to all the reasons stated below EXCEPT

• It is inert and does not react with compounds under study.

• The hydrogen nuclei in TMS are highly shielded because silicon has a low electronegativity.

• TMS shift depends on temperature and concentration.

• It gives one strong sharp peak because it is caused by the combined effect of 12 equivalent hydrogen atoms.

Tags

NGSS.HS-PS1-5