Interpreting Mass Spectra Flashcards

1️⃣ Familiarise yourself with the flashcards:

  • Look through all the flashcards to see what's on both sides.
  • Make sure you understand the information on each card. If something's unclear, click the link to the revision notes at the bottom of the page for more details.

2️⃣ Test yourself:

  • Look at the question or prompt on each card and try to remember the answer before flipping it over.
  • Check the answer and make a note of any cards you find challenging and need to go over more.

3️⃣ Consistently Review and Practice:

  • Use spaced repetition: spend more time on the cards you struggle with and go over them more often.
  • Regularly review all the flashcards to help you better understand and retain the information over time.

Note: We may include questions that have multiple correct answers. It's useful to remember specific examples to understand these concepts better.

PERSONALISED 1-TO-1 TUTORING

Need more help on this topic? Get 1-to-1 support

Get support with clear explanations, practice and feedback (Ages 5 to 16).

  • DBS-checked tutors
  • Flexible times
  • Parents can be updated

Want an ad-free experience? Subscribe to remove ads

What is a mass spectrum?

A mass spectrum is a graph that shows the ions from a sample and how many of each type there are.

What is shown on the horizontal (x) axis of a mass spectrum?

The horizontal axis shows the mass/charge ratio, written as m/z, for the ions.

What is shown on the vertical (y) axis of a mass spectrum?

The vertical axis shows the relative abundance, which tells you how common each ion is compared with the others.

What is the molecular ion peak in a mass spectrum?

The molecular ion peak is the peak at the highest m/z value that comes from the whole molecule with one positive charge.

How do you find the relative formula mass (Mr) of a compound from its mass spectrum?

Find the molecular ion peak and read its m/z value; this value is the Mr of the compound.

If the molecular ion peak is at m/z = 58, what is the relative formula mass (Mr) of the compound?

The relative formula mass (Mr) of the compound is 58.

Why does a mass spectrum often show many smaller peaks at lower m/z values than the molecular ion peak?

These smaller peaks are caused by fragments of the original molecule that have broken into smaller ions.

What is the tallest peak in a mass spectrum called, and what does it show?

The tallest peak is called the base peak, and it shows the ion with the greatest relative abundance in the sample.

Why can the pattern of peaks in a mass spectrum be used like a fingerprint for a substance?

Because each substance has its own unique pattern of peaks, you can match an unknown spectrum to a known one to identify the substance.

How can isotopes of an element affect its mass spectrum?

Isotopes have different masses, so they produce more than one peak close together on the spectrum for that element.