Question 1

Which scientist is credited with inventing the mass spectrometer, and in what year?

Accepted Answer

Francis Aston in 1919

Question 2

What is the primary purpose of mass spectrometry in organic chemistry?

Accepted Answer

To measure the mass of atoms or molecules

Question 3

Which of the following is NOT a key step in the operation of a mass spectrometer?

Accepted Answer

Crystallisation of the sample

Question 4

In mass spectrometry, what does the x-axis of a mass spectrum graph represent?

Accepted Answer

Mass to charge ratio ($$m/z)$$

Question 5

Why is carbon-12 used as the standard in mass spectrometry?

Accepted Answer

It provides a reference for determining the mass of other isotopes

Question 6

A mass spectrum of magnesium shows three peaks. What does this indicate?

Accepted Answer

Magnesium has three naturally occurring isotopes

Question 7

Which real-world application would most likely use mass spectrometry for protein identification?

Accepted Answer

Medical diagnostics

Question 8

If a sample contains two isotopes with masses $$m_1 = 10$ and m_2$ = 12$$, and their relative abundances are 75% and 25% respectively, what is the average atomic mass of the element?

Accepted Answer

$$10.5$$

Question 9

Which step in mass spectrometry involves the use of high energy electrons?

Accepted Answer

Ionisation of the vaporised sample

Question 10

A forensic scientist uses mass spectrometry to analyze a sample from a crime scene. What information can they obtain?

Accepted Answer

The molecular structure and isotopic composition of the sample

Question 11

What does the height of each peak in a mass spectrum represent?

Accepted Answer

The relative abundance of ions with a specific mass to charge ratio

Question 12

Which of the following best describes the separation of ions in a mass spectrometer?

Accepted Answer

Ions are separated based on their mass to charge ratio ($$m/z)$$

Question 13

If a mass spectrum of aluminum shows only one peak, what does this suggest about aluminum?

Accepted Answer

Aluminum has only one naturally occurring isotope

Question 14

Which of the following is a common misconception about mass spectrometry?

Accepted Answer

It measures the mass of atoms and molecules directly without ionisation

Question 15

A sample contains two isotopes: $$^{35}Cl (75$$%) and $$^{37}Cl (25$$%). Calculate the average atomic mass of chlorine.

Accepted Answer

$$35.5$$

Question 16

Which of the following best explains why mass spectrometry is useful in scientific research?

Accepted Answer

It allows precise identification and quantification of isotopes and molecules

Question 17

In mass spectrometry, what does the term 'relative abundance' refer to?

Accepted Answer

The proportion of each isotope present in a sample compared to the total

Question 18

Which of the following is NOT an example of mass spectrometry analysis?

Accepted Answer

Determining the boiling point of a compound

Question 19

A mass spectrometer separates ions based on their $$m/z$$ ratio. If an ion has a mass of $$24$$ and a charge of $$+2$$, what is its $$m/z$$ value?

Accepted Answer

$$12$$

Question 20

Which process in mass spectrometry is responsible for counting the number of ions of different mass to charge ratios?

Accepted Answer

Detection

Mass Spectrometry: Principles and Applications in Organic Chemistry

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