Porous Frameworks: Pores, Guests and Stability · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Solids built around empty space

Science · Chemistry · ages 22-23
Name ______________________   Date ____________

  1. What does the uptake plateau of an isotherm give?

    • The pore volume
    • The linker colour
    • The lab temperature

  2. In a porous framework, what is the useful part?

    • The empty space inside
    • The outer paint layer
    • The shipping container

  3. Gentle activation such as supercritical drying helps fragile frameworks survive solvent removal.

    Circle one:   True   False

  4. A fresh framework loses all uptake after normal drying. What happened?

    • The gases refused to enter
    • The isotherm machine broke
    • The pores collapsed under capillary forces

  5. Two gases match in size but differ in polarity. Which framework separates them?

    • One with wider pores only
    • One with a polar inner surface
    • One with thicker outer walls

  6. An isotherm climbs steeply at low pressure then flattens. What do you conclude?

    • Weak binding with huge pores
    • Strong binding with a defined pore volume
    • No pores at all

  7. A storage task needs methane held strongly at low pressure. Which property do you specify?

    • Pores sized to methane with a strongly attracting surface
    • The largest pores synthesis allows
    • The cheapest nodes regardless of fit

  8. A longer linker is proposed to raise capacity for a small gas. What is the flaw?

    • Longer linkers always help every gas
    • Linker length never matters
    • Bigger pores can weaken binding and invite collapse
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Answer key

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

Solids built around empty space W1-mt_csqPeYIhN6-s1

  1. The pore volume · Full pores stop taking up guest, and that level reads as volume.
  2. The empty space inside · Guests are stored and separated in the pores.
  3. True · Weak capillary forces leave the walls standing.
  4. The pores collapsed under capillary forces · Lost uptake after drying is the signature of collapse.
  5. One with a polar inner surface · Size admits both, so surface chemistry must do the picking.
  6. Strong binding with a defined pore volume · The steep rise means strong grip and the plateau means filled pores.
  7. Pores sized to methane with a strongly attracting surface · Low-pressure uptake demands fit plus strong binding working together.
  8. Bigger pores can weaken binding and invite collapse · Capacity gains can cost selectivity and stability.
Worksheet · LightMySky