IB Topics 11 & 21

What information about 2-hydroxybutanoic acid can be inferred through mass spectrometry, MS, infrared spectroscopy, IR, and proton nuclear magnetic resonance spectroscopy, ¹H NMR?

• A

• B

• C

• D

What information can be deduced about a compound through X-ray crystallography?

• Boiling and melting points

• Bond Angles

• Bonds that will break during fragmentation

• Ionization energy

Which organic compound has the ¹H NMR shown?

• Methanal

• Ethanoic acid

• Methyl ethanoate

• Propanoic acid

A student performed an experiment to find the melting point of sulfur, obtaining 118.0 °C. The literature value is 115.2 °C. What was the percentage error?

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• 
• 
• 

Which compound produces this mass spectrum?

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What is the index of hydrogen deficiency (IHD) of this molecule? Paracetamol (acetaminophen)

• 3

• 4

• 5

• 6

How many signals are observed in the ¹H NMR spectrum of this compound?

• 1

• 2

• 3

• 4

What is the uncertainty, in cm³, of this measurement?

• ±0.01

• ±0.1

• ±10

• ±1

Burette readings for a titration are shown. What is the mean titre? (average volume used)

• 11.1 cm³ ± 0.1 cm³

• 11.15 cm³ ± 0.05 cm³

• 11.2 cm³ ± 0.05 cm³

• 11.2 cm³ ± 0.1 cm³

Which spectra would show the difference between propan-2-ol, CH₃CH(OH)CH₃, and propanal, CH₃CH₂CHO? (choose all that are correct)

I.   mass
II.  infrared
III. ¹H NMR

• I

• II

• III