Domain: Healthcare — Pharmaceutical Chemistry
Target concept: Identification of 2,4-Dinitrophenylhydrazine

Video generation prompt: Take a small amount of acetone into a transparent test tube, add 2 mL of 2,4-dinitrophenylhydrazine reagent, heat under a water bath at 40°C for 2 minutes, and observe the reaction phenomenon.

Evaluation guide:
(i) Target concept: Visual confirmation of carbonyl group detection via 2,4-DNPH derivatization. Minimum mechanism: Acetone (ketone) must be present and react with 2,4-DNPH under controlled thermal activation to generate an insoluble hydrazone; this requires molecular compatibility, aqueous-organic miscibility, and thermally driven condensation, resulting in irreversible solid-phase formation with diagnostic yellow-orange color.
(ii)Storyline: [Frame 0–2s] Colorless acetone dispensed into transparent test tube → [Frame 2–4s] Orange-yellow reagent poured from labeled bottle into same test tube → [Frame 4–6s] Test tube lowered into visible water bath with stable water surface → [Frame 6–8s] Thermal incubation shown via sustained immersion (no boiling, no steam burst) → [Frame 8–10s] Observer looks directly at test tube; yellow-orange precipitate is fully formed, settled, and visually dominant against colorless supernatant. All events occur within a single fixed wide shot; no cuts; no object enters/exits frame except reagent stream; viewpoint remains orthogonal to test tube long axis; lighting ensures full visibility of precipitate morphology and color.

Manual:
Experimental Procedure
1. Place colorless acetone into a transparent test tube.
2. Add 2 mL of orange-yellow 2,4-dinitrophenylhydrazine reagent.
3. Place test tube in water bath at ~40°C for 2 min.
4. Observe test tube contents.
Observation of Experimental Phenomena
Formation of a dense, opaque, yellow-orange crystalline precipitate in the test tube after heating.
Summary of Experimental Principles
2,4-DNPH reacts selectively with carbonyl groups (e.g., in acetone) under mild heating to form hydrazone derivatives — insoluble yellow-orange solids used to identify aldehydes/ketones.

Prompt Grounding rubric:
level_1: No transparent test tube is shown; the colorless acetone, the 2,4-dinitrophenylhydrazine (2,4-DNPH) reagent, and the water bath are all absent; no heating or observation step is depicted: the scene shows nothing resembling the described carbonyl spot-test setup.
level_2: Only one of the required elements appears (for example a test tube or a beaker of liquid), but the acetone, the 2,4-DNPH reagent, and the water bath do not all appear together; the reagent is never added to the test tube, no heating step is shown, and no final observation moment occurs.
level_3: A transparent test tube holding colorless acetone, the orange-yellow 2,4-DNPH reagent, and a water bath are all present, and the reagent is added to the test tube, the tube is heated in the bath, and the contents are observed afterward, but one detail is off, such as the reagent appearing colorless instead of orange-yellow, the reagent stream entering from off-screen with no visible bottle, or the observation shot coming before the heating step.
level_4: The test tube, the colorless acetone, the orange-yellow 2,4-DNPH reagent, and the water bath are all correctly colored and shaped, and the five steps (dispensing acetone, adding reagent, immersing in the water bath, holding through the heating period, and the final observation) occur in the correct order with the reagent bottle and water bath positioned near the test tube throughout; only one small flaw remains, such as an unreadable reagent-bottle label or faint, inconsistent steam above the bath.
level_5: Every element matches the prompt precisely: a transparent test tube holding colorless acetone receives 2 mL of orange-yellow 2,4-DNPH reagent poured from a visibly labeled bottle, the tube is immersed in a calm water bath for the full heating period with no boiling or splashing, and the final shot clearly shows attention directed at the test tube's contents; the reagent bottle, test tube, and bath stay logically arranged with no readable flaw in object identity, color, or step order.

Scientific and Causal Correctness rubric:
level_1: The test tube's contents show no visible change after heating (no color shift and no precipitate), so nothing in the video indicates the carbonyl-detection reaction between acetone and 2,4-DNPH ever took place.
level_2: The liquid changes color (for example turning more yellow) but no solid ever separates out, or a precipitate forms but it is white or gray rather than yellow-orange, or a precipitate is already visible before the reagent has even been added, none of which matches how the acetone + 2,4-DNPH reaction actually proceeds.
level_3: A yellow-orange precipitate appears only after the reagent has been added and heating has begun, correctly reflecting the acetone + 2,4-DNPH reaction, but the timing is imprecise: for instance the precipitate is visible while the tube is still outside the water bath, the reagent liquid itself is shown as colorless instead of orange-yellow, or the solid stays suspended rather than beginning to settle.
level_4: A granular yellow-orange precipitate forms only once the acetone-and-reagent mixture has been heated, is clearly a separate solid phase from the surrounding liquid, and stays stable once the tube is removed from the bath, correctly showing that heat plus both reactants are needed to trigger the hydrazone precipitate; the only shortcoming is minor, such as the precipitate looking slightly translucent or a background tint that makes the hue a little hard to read without changing what color it obviously is.
level_5: The colorless acetone and orange-yellow reagent stay mixed and unreacted before heating; once the water bath heats the tube, a dense, opaque, unmistakably yellow-orange solid separates out and settles to the bottom, and it stays exactly as it is through the rest of the observation: no precipitate appears before heating, none appears without both acetone and reagent present, and the color never shifts afterward, matching the expected hydrazone-formation chemistry exactly.

Spatiotemporal Consistency rubric:
level_1: The test tube, reagent bottle, or water bath vanishes and reappears, or the liquid level inside the tube jumps to a different amount between shots with no pouring shown; the room lighting suddenly switches from bright to dim or back with nothing in the scene to explain the change, or the tube's shape or the liquid's meniscus warps in a way that ignores gravity.
level_2: One clearly jarring break occurs: for example the test tube is full in one moment and empty the next with no pour shown, the reagent seems to appear inside the tube with no visible stream from the bottle, or the tube goes from resting on the counter to fully submerged in the water bath in a single instant with no motion shown in between.
level_3: The test tube, reagent bottle, and water bath keep a steady size, position, and orientation across the shot, and every motion (pouring, lowering into the bath, the final observation) flows continuously without jumps or lighting flicker; still, one small hiccup is visible, such as the liquid's meniscus wobbling oddly while everything else is still, or the reflection on the tube's glass briefly looking inconsistent for a moment.
level_4: There is no teleporting, warping, or lighting jump anywhere in the shot; the acetone pour, the lowering of the tube into the water bath, and the final observation are all shown with natural, gradually changing motion, and the liquid's surface and meniscus behave the way a real liquid would; the only shortcoming is minor and non-disruptive, such as a faint reflected-light flare on the glass or slight blur during the fastest part of the pour.
level_5: The test tube, reagent bottle, and water bath hold their shape, proportions, and position believably throughout with no visible flicker or warping at any point; the reagent stream pours smoothly at a steady rate, the liquid's meniscus and any gentle heat-induced ripple in the water bath look physically natural, and if anyone leans in to observe, they move slowly and smoothly; overall the sequence looks like an ordinary, uninterrupted recording of the experiment.