Domain: Healthcare — Pharmaceutical Chemistry
Target concept: Ibuprofen-metal ion complexation (copper ion method)

Video generation prompt: Dissolve ibuprofen in ethanol, and gradually add copper(II) sulfate aqueous solution under stirring, observing the complexation reaction process. Clearly present the sequential order of experimental procedures: preparation of solutions, addition and mixing of reagents. Use beaker, dropper, and glass rod. Emphasize each step of the metal-drug coordination reaction.

Evaluation guide:
(i) Target concept: Metal–drug coordination complex formation via ligand substitution in solution, visualized by ligand-field-induced color change.
Minimum mechanism: Cu²⁺ must be octahedrally coordinated in [Cu(H₂O)₆]²⁺ (blue) in aqueous solution; upon addition to ethanolic ibuprofen, labile water ligands are displaced by ibuprofen anions, forming a lower-symmetry Cu(II)–ibuprofen complex with altered d-orbital splitting → observable shift in visible absorption band (blue → greenish-blue/olive).
(ii)Storyline: Frame 1–3: White ibuprofen crystals rest in dry beaker → ethanol poured in → crystals disperse and vanish (dissolution complete). Frame 4–6: Blue droplet emerges from dropper tip and contacts ethanol surface → localized greenish-blue halo forms instantly at impact site. Frame 7–10: Glass rod enters, stirs → halo expands radially → entire solution homogenizes to uniform greenish-blue/olive hue; no settling, no cloudiness, no color reversion. Fixed overhead/slightly angled viewpoint; all tools and beaker remain in same relative positions; lighting constant; no cuts or re-framing.

Manual:
Experimental Procedure
1. Place white ibuprofen solid into a clean beaker; add ethanol to dissolve it completely with glass rod stirring.
2. Using a dropper, slowly add blue copper(II) sulfate aqueous solution into the beaker.
3. Continue stirring with glass rod until color stabilizes.
Observation of Experimental Phenomena
- Ibuprofen solid dissolves in ethanol to give a colorless, transparent solution.
- Blue copper(II) sulfate solution mixes in and induces immediate greenish-blue or olive-green color development.
- Final mixture is homogeneous, transparent, and stable with no precipitate.
Summary of Experimental Principles
Ibuprofen contributes only its single carboxylate group (-COO-) as the donor to Cu(II). Rather than forming a mononuclear square-planar chelate, documented Cu(II)-ibuprofen complexes adopt a dinuclear 'paddle-wheel' structure (as in copper(II) acetate): two Cu(II) centers are bridged by four carboxylate groups, with solvent molecules (water/ethanol) occupying the remaining axial coordination sites on each copper. This altered coordination environment relative to free aqueous Cu2+ shifts the d-d transition energy, producing the observed color change from blue toward greenish-blue/olive.

Prompt Grounding rubric:
level_1: None of the required items appear: no white ibuprofen solid, no ethanol, no blue copper(II) sulfate solution, no beaker, no dropper, and no glass rod; and none of the three steps (dissolving, adding, stirring) are shown.
level_2: At least one of the correct items appears (e.g., a beaker or a dropper) and something like adding or stirring is attempted, but the ibuprofen solid, the ethanol, or the blue copper sulfate solution is missing, and there is no clear step-by-step order among dissolving, adding, and stirring.
level_3: All three required substances appear with their correct look: white ibuprofen crystals, colorless ethanol in the beaker, and blue copper(II) sulfate solution in the dropper; and all three actions (dissolving the ibuprofen in ethanol, dispensing the copper sulfate solution from the dropper, and stirring with the glass rod) are shown, but the order is wrong (e.g., the copper solution is added before the ibuprofen has dissolved) or one action lacks a clear moment of the tool actually touching the liquid or beaker.
level_4: Everything in the 3-point level holds, and additionally the three actions occur in the correct order: ibuprofen dissolves in the ethanol first, then the blue copper(II) sulfate solution is dispensed from the dropper into the beaker, then the glass rod stirs the mixture; and each action clearly shows the tool contacting the liquid (the solid visibly meets the ethanol, the dropper tip visibly reaches into the beaker, the glass rod is visibly submerged while stirring).
level_5: Everything in the 4-point level holds, and additionally: the dropper is held upright over the beaker while dispensing rather than at a sharp angle; the glass rod stays in the liquid for the whole stirring action rather than being lifted out partway through; the ibuprofen is shown fully dissolved before the copper sulfate solution is added, so no undissolved clumps are visible once the copper solution goes in; and the beaker, dropper, and glass rod all stay in the same general arrangement on the table throughout, without any of them abruptly moving to a new location or vanishing from view.

Scientific and Causal Correctness rubric:
level_1: No color change happens at all: the mixture stays colorless or stays the plain blue of the copper sulfate solution the whole time; the ibuprofen looks like it never dissolves; there's no sign that the copper solution and the dissolved ibuprofen are interacting.
level_2: A color change happens but the wrong way: for example the mixture turns green, yellow, or brown instead of greenish-blue/olive, or the color changes before the copper sulfate solution has even been added, or the ibuprofen crystals stay clearly undissolved in the ethanol even after stirring.
level_3: The ibuprofen fully dissolves in the ethanol to give a colorless solution; the blue copper sulfate solution is then added; after the addition and stirring, the mixture becomes a greenish-blue or olive color, but the color looks patchy or streaky, or fades again, rather than settling into one even shade.
level_4: The events happen in the right cause-and-effect order and look right: the ibuprofen solid contacts the ethanol and fully dissolves into a clear, colorless liquid; the blue copper sulfate solution then contacts this liquid and an immediate greenish-blue/olive tint appears where it lands; stirring then spreads this tint until the whole beaker looks a single uniform greenish-blue/olive color, with no leftover solid, cloudiness, or separate layers.
level_5: Everything in the 4-point level holds, and additionally: the final greenish-blue/olive color looks even and uniform across the whole beaker in the last part of the video, with no part of the beaker looking noticeably lighter or darker than the rest; the color only starts spreading once the glass rod is actively stirring, rather than spreading on its own while the rod is still; and no unrelated colors (like purple, yellow, or a whitish cloudy patch) show up anywhere in the mixture.

Spatiotemporal Consistency rubric:
level_1: The beaker, dropper, or glass rod is missing from a frame and then shows up again somewhere else in the shot with no motion connecting the two positions; the glass rod spins at an impossible speed and then instantly freezes in place; the ethanol or mixture's surface jumps to a different height with nothing shown to cause it; the lighting changes drastically between consecutive frames with no visible cause; or the video cuts between very different camera angles (e.g., from overhead to an extreme close-up to a side view) with no smooth transition between them.
level_2: One clear major break occurs: for example, the dropper tip is shown touching the liquid surface in one moment but the liquid level or color hasn't changed at all right after, or the glass rod is shown stirring and then is suddenly missing from the beaker in the next moment with no withdrawal shown, or the ethanol level rises or falls by more than about a third of its height with no dispensing or spilling to explain it.
level_3: Small but noticeable slips occur: the stirring motion has a brief, plainly visible shake rather than a perfectly smooth rotation; the dropper tip is briefly hidden from view during dispensing but it's still clear that dispensing is happening; the beaker looks like it shifts slightly in place across the video; none of these slips make the liquid's meniscus shape or the tools' orientation look implausible.
level_4: The beaker, dropper, and glass rod stay visible and move in a physically sensible way throughout: the dropper comes down into frame and dispenses smoothly, without jerky motion, then pulls back out smoothly; the glass rod turns at a steady, continuous speed while staying at a consistent depth in the liquid; the ethanol surface dips and swirls in a way that matches gentle stirring rather than snapping into odd shapes; the dropper tip is never so hidden that you can't tell dispensing is happening.
level_5: Everything in the 4-point level holds, and additionally: the beaker does not visibly shift position at any point in the video; the curve of the liquid surface where it meets the beaker wall keeps matching the beaker's shape the whole time; the glass rod's turning looks smooth from start to finish, without any sudden stutter or unnatural blur; the dropper moves straight down toward the beaker's center rather than drifting sideways; and reflections/highlights on the glass beaker do not abruptly pop in or out of existence between moments.