Resolution, Efficiency and the van Deemter Curve · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Splitting peaks at the best speed

Science · Chemistry · ages 19-20
Name ______________________   Date ____________
  1. Which source rules at slow flows?

    • Diffusion
    • Hopping lag
    • Eddy paths
  2. What marks a clean baseline split?

    • Resolution 0.5
    • Resolution 1.0
    • Resolution 1.5
  3. Eddy spreading stays about flat as flow changes.

    Circle one:   True   False

  4. Why does the curve rise again past the best flow?

    • Eddy paths vanish
    • Hopping lag grows with speed
    • Diffusion returns
  5. Peaks at 100 and 106 seconds, widths 4 and 4. Type the resolution.

    Answer: ______________

  6. Where is the best flow on the curve?

    • At the lowest dip
    • At the far fast end
    • At the far slow end
  7. A fair gap with wide peaks is best fixed by a longer column at the best flow.

    Circle one:   True   False

  8. Two peaks overlap with almost no gap. What is the best fix?

    • Run the same column much longer
    • Change to a more selective phase
    • Push the flow to maximum
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Splitting peaks at the best speed W1-mt_RUjdSb5Rgw-s1

  1. Diffusion · Slow flows let diffusion spread peaks most.
  2. Resolution 1.5 · At 1.5 the peaks just separate fully.
  3. True · Path differences ignore speed.
  4. Hopping lag grows with speed · Fast flows outrun hopping between phases.
  5. 1.5 · Two times 6 over 8 equals 1.5.
  6. At the lowest dip · The dip balances diffusion against hopping lag.
  7. True · That pattern marks an efficiency problem.
  8. Change to a more selective phase · A near-zero gap needs selectivity, not length.
Worksheet · LightMySky