Finding molecules in an ionization chamber

Question

Assignment:

Question 1. When a high energy electron impacts molecule M in the ionization chamber of a mass spectrometer, what type of species is initially produced?

a) cation
b) anion
c) radical cation
d) radical anion

Question 2. What compound would be expected to show intense IR absorption at 3300 cm-1?
a. 2-butyne
b. butane
c.1-butene
d.1-butyne

Question 3. Ethyne (H-C=C-H) does not show IR absorption in the region 2000-2500 cm-1 because:
a. there is no change in the dipole moment when the CC bond in ethyne stretches
b.there is a change in the dipole moment when the CC bond in ethyne stretches.
c.C-H stretches occur at lower energies.
d.CC stretches occur at about 1640 cm-1.

Question 4. Which compound would show a larger than usual M+2 peak?
a. CH₃CH₂SCH₃
b. (CH₃)₂CHNH₂
c. CH₃CH₂CO₂H
d. CH₃(CH₂)₂CH₃

Question 5. Which of the following fragment peaks would not be expected in n-hexane?
a. 43
b. 57
c. 71
d. 87