Domain: Healthcare — Pharmaceutical Chemistry
Target concept: Morphine Detection

Video generation prompt: Transfer an appropriate amount of morphine sample into a test tube, add formaldehyde-sulfuric acid reagent, and observe the solution inside the test tube.

Evaluation guide:
(i) Target concept: Colorimetric identification of morphine via Marquis reaction.
Minimum mechanism: Morphine must be present as solid-phase analyte; formaldehyde-sulfuric acid must be delivered as aqueous/acidic reagent; intimate contact between solid and liquid must occur; electron delocalization in resulting cationic dye must generate purple/violet absorbance in visible spectrum, requiring no external catalyst, heating, or time delay beyond immediate mixing.
(ii)Storyline: [Frame 0–2] Empty test tube centered, static. [Frame 3–5] Hand deposits discrete white crystalline pile inside tube (no dissolution yet). [Frame 6–8] Colorless liquid stream enters tube, contacts crystals, fills lower portion. [Frame 9–10] Purple/violet color emerges *only* where liquid contacts crystals and spreads upward through liquid column: no color in air space, no color on tube walls, no color before contact. Perspective: Fixed frontal close-up, shallow depth of field, tube occupying ≥60% vertical frame, no occlusion of tube interior.

Manual:
Experimental Procedure
1. Place an empty clear glass test tube upright on bench.
2. Transfer a small amount of white crystalline morphine solid into the tube.
3. Add formaldehyde-sulfuric acid reagent (colorless liquid) into the same tube.
Observation of Experimental Phenomena
A distinct purple or violet color develops uniformly within the liquid phase inside the test tube, exclusively after reagent addition and contact with morphine.
Summary of Experimental Principles
Morphine reacts with formaldehyde-sulfuric acid (Marquis reagent) to form a conjugated quinoidal compound exhibiting characteristic purple/violet color — a specific colorimetric identification reaction in pharmaceutical chemistry.

Prompt Grounding rubric:
level_1: No test tube is shown, or no white crystalline morphine sample is shown, or no formaldehyde-sulfuric acid reagent (or its addition) is shown, or the sequence never depicts both a solid sample and a liquid reagent being combined in a tube.
level_2: A test tube is visible, and either the white crystalline morphine sample or the colorless reagent liquid is shown, but not both, with no depiction of transferring the missing substance into the tube.
level_3: An empty test tube is shown at the start; a small amount of white crystalline morphine is visibly transferred into it; formaldehyde-sulfuric acid reagent (colorless liquid) is then visibly added into the same tube so that liquid is visible inside after addition; morphine and reagent are both clearly present and correctly placed in the one tube.
level_4: All conditions of the 3-point level hold, and the morphine crystals are added strictly before the reagent, matching the prompt's stated order; no second tube, extra container, or unrelated substance appears in the shot; the camera stays fixed on the test tube throughout, and neither substance is swapped for a visually different one (e.g., no colored crystals standing in for morphine, no colored liquid standing in for reagent).
level_5: All conditions of the 4-point level hold, and the morphine appears as a small, discrete pile of loose white crystals (not a fine powder cloud, not a solid clump, not already dissolved); the reagent stream enters the tube smoothly with no spillage over the rim and no splashing out; the tube remains upright and still throughout; the entire sequence (empty tube, crystal addition, reagent addition, and settling) is shown in one continuous, unbroken shot with the crystal-to-liquid contact clearly visible.

Scientific and Causal Correctness rubric:
level_1: The liquid in the tube stays colorless throughout, or a color other than purple/violet appears (e.g., blue, green, yellow, brown), or a purple/violet color appears before the reagent has been added to the crystals.
level_2: A purple or violet tint appears, but it does not behave like a real Marquis reaction: it shows up only as a thin surface film rather than through the liquid, it fades away again within a moment of appearing, or it appears outside the tube (e.g., as a stain on the outside of the glass or on the bench) rather than in the liquid inside the tube.
level_3: Once the reagent contacts the morphine crystals, a purple/violet color visibly develops inside the liquid within the test tube; the color is confined to the liquid, not the crystal solid or the air above it, and is not masked by any other dominant color such as brown or black.
level_4: All conditions of the 3-point level hold, and the purple/violet color spreads outward from the point of contact and fills the liquid fairly evenly within a few seconds of screen time, then holds steady for at least 2 seconds with no fading back toward colorless and no separating into colored and clear layers; no bubbling, smoke, or other unrelated effect distracts from the color change.
level_5: All conditions of the 4-point level hold, and the purple/violet color ends up filling more than 90% of the liquid volume with an even, streak-free hue, with almost none of the original colorless liquid left visible by the end of the clip; the transition from colorless to fully purple/violet happens within a short, continuous stretch of the video right after contact begins, rather than after a long unexplained delay or as a sudden jump-cut.

Spatiotemporal Consistency rubric:
level_1: The test tube is absent from one frame and then shows up again in a different position with no visible motion connecting the two states; the crystals or the reagent stream jump from one spot to another with no visible path between; the overall lighting flips from dark to bright, or the reverse, within a single frame with no clear cause; the tube's orientation suddenly changes by more than 45 degrees with no hand visibly touching it.
level_2: The test tube tips or wobbles sharply, tilting more than roughly 30 degrees, during the pour; the reagent stream appears disconnected from its source container partway through pouring; crystals appear to float or hover above the liquid surface instead of resting in it; the liquid's surface takes on a shape that is not physically possible for a liquid at rest, such as bulging upward into a dome.
level_3: The test tube stays upright and in place throughout; the crystals are placed into the tube with a steady, visible hand motion; the reagent is poured as one continuous stream that enters the tube opening; the liquid surface shows a normal, gently curved edge where it meets the glass; no part of the scene flickers or vanishes.
level_4: All conditions of the 3-point level hold, and the hand's motion is smooth and natural throughout, without sudden jerks or unnaturally long pauses; the pour stream keeps a steady thickness and path from bottle to tube; the tube itself does not shake or vibrate; the crystals in the foreground and the tube wall behind them stay in consistent visual relation to each other as the camera view holds steady.
level_5: All conditions of the 4-point level hold, and the test tube's position and the crystal pile's position stay visually steady across the whole clip with no perceptible drift or repositioning; there is no visible frame skipping or repeated-frame stutter; the illumination stays even with no flickering; the liquid surface shows only gentle, natural ripples and never freezes into an unnaturally still, glassy state nor snaps abruptly to a new shape; the crystals continue to look solid and opaque against the clear liquid throughout, with that visual relationship never breaking.