Domain: Healthcare — Pharmaceutical Chemistry
Target concept: Rapid Determination of Calcium Gluconate Content (Calcium Carboxylic Indicator Method)

Video generation prompt: Pipette a specific volume of calcium gluconate injection into a conical flask, add distilled water and a suitable amount of sodium hydroxide solution to make the medium strongly alkaline, then add a small amount of calconcarboxylic acid (Cal-Red) indicator. Titrate with a standardized EDTA solution while gently swirling, until the endpoint is reached. Display only the clear titration procedure, reagents used, glassware, and hand operations.

Evaluation guide:
(i) Target concept: Visual confirmation of a calcium gluconate titration endpoint via a calconcarboxylic acid (Cal-Red)-mediated color transition under alkaline conditions.
Minimum mechanism: The solution must first be made strongly alkaline with sodium hydroxide; calconcarboxylic acid indicator must be present as a color-forming dye; calcium ions initially bind the indicator to form a wine-red/purplish-red complex; EDTA must displace calcium from the indicator complex in stoichiometric fashion as titrant is added; free indicator at high pH must appear pure blue under ordinary ambient lighting (no UV or fluorescence is involved); all transitions require direct physical contact and sequential reagent addition.
(ii) Storyline: [Frame 0-2] Pipette approaches and inserts into conical flask -> [Frame 3-4] Calcium gluconate dispensed -> [Frame 5] Distilled water and sodium hydroxide solution added -> [Frame 6] Calconcarboxylic acid indicator vial brought adjacent, droplets released -> [Frame 7] Wine-red/purplish-red color appears uniformly in flask -> [Frame 8] EDTA burette tip positioned above flask, dispensing begins -> [Frame 9] Swirling initiates synchronously with EDTA contact -> [Frame 10] Wine-red color fades progressively -> [Frame 11] Pure blue color emerges fully and homogeneously -> [All frames] Fixed frontal viewpoint, no occlusion of flask interior, consistent lighting, no object teleportation or structural break.

Manual:
Experimental Procedure
1. Hold pipette, draw calcium gluconate injection, and dispense into conical flask.
2. Add distilled water and sodium hydroxide solution to the flask to make it strongly alkaline.
3. Add calconcarboxylic acid (Cal-Red) indicator (a wine-red/purplish-red-forming dye at high pH).
4. Titrate with standardized EDTA solution while gently swirling the flask until the endpoint.
Observation of Experimental Phenomena
A wine-red/purplish-red color appears after indicator addition; upon EDTA titration, this color fades and the solution turns pure blue at the endpoint.
Summary of Experimental Principles
At high pH, calcium ions bind calconcarboxylic acid indicator to form a wine-red complex; EDTA chelates Ca2+ more strongly than the indicator does, releasing free indicator, which appears pure blue at the same high pH.

Prompt Grounding rubric:
level_1: No pipette, no conical flask, no EDTA solution bottle or burette, and no calconcarboxylic acid indicator container are shown; none of the objects required for the calcium gluconate titration appear in the video.
level_2: At least one required object appears (for example, only the flask or only the EDTA bottle), but no pipetting action occurs, no liquid is transferred into the flask, no indicator is added, and no titration motion is shown; the core actions of the procedure are missing.
level_3: The pipette is held and inserted into the conical flask, distilled water and sodium hydroxide solution are visibly dispensed into the flask, and a small amount of calconcarboxylic acid indicator is added; the EDTA solution bottle or burette is present and held near the flask, but no titration motion (no controlled dispensing from the burette or dropper into the flask) is shown.
level_4: All required objects are present and correctly identified: pipette, conical flask, distilled water and sodium hydroxide containers, calconcarboxylic acid indicator vial, and EDTA solution bottle/burette; pipetting into the flask, addition of water and NaOH, addition of indicator, and the start of titration (visible dispensing of EDTA solution into the flask while the flask is gently swirled) occur in the correct order; however, the swirling is interrupted or the flask's orientation shifts abruptly between steps.
level_5: All required objects are present and recognizable by their form (pipette with a calibrated scale, conical flask with a tapered body, EDTA burette with a stopcock or a clearly labeled bottle), and every action occurs in the correct sequence: (1) the pipette draws and delivers calcium gluconate injection into the conical flask, (2) distilled water and sodium hydroxide solution are added, (3) the calconcarboxylic acid indicator is added as a visible, distinct droplet stream, (4) EDTA solution is dispensed steadily from the burette or bottle into the flask while the flask is continuously and smoothly swirled - all actions fully visible, unobstructed, and spatially coherent within a fixed camera view.

Scientific and Causal Correctness rubric:
level_1: No color change occurs; the solution stays colorless throughout, or any color that appears is not wine-red/purplish-red (for example it looks blue, green, or yellow immediately after indicator addition, with no earlier color stage); the calconcarboxylic acid indicator is absent or clearly replaced by a different reagent.
level_2: Calconcarboxylic acid indicator is added, but no wine-red/purplish-red color is visible in the solution before EDTA is dispensed; EDTA is dispensed but no color transition occurs; or the resulting color is the wrong hue (for example orange, brown, or a color that stays green throughout).
level_3: A wine-red/purplish-red color appears in the solution after indicator addition (a distinct reddish-purple tint is visible in the conical flask); EDTA dispensing begins; the color eventually shifts toward blue at the endpoint, but the transition is out of order - for example the red color fades before EDTA touches the solution, or blue appears without a preceding fade from red.
level_4: The wine-red/purplish-red color is clearly visible in the solution after indicator addition; once the EDTA solution contacts the solution, the red color gradually fades; the pure blue endpoint color appears only after sustained EDTA addition and coincides with the swirling coming to rest; there is no premature or delayed color shift, and the sequence follows the causal chain: indicator plus Ca2+ at high pH gives a wine-red complex, then EDTA chelates the Ca2+ and releases the free indicator, which appears blue.
level_5: The wine-red/purplish-red color is vivid and evenly spread through the conical flask after indicator addition, and stays stable until the first EDTA drop touches the solution; it then fades continuously and evenly across the whole volume; a pure blue color appears fully and uniformly only after the last drop of EDTA, with no reddish patches left behind; the color change is a one-way, complete transition that happens only during active titration, with no shift before EDTA contact or after swirling stops.

Spatiotemporal Consistency rubric:
level_1: The pipette, conical flask, EDTA burette, or indicator vial appears or disappears abruptly between frames with no visible path of motion (for example the flask is suddenly full of liquid with no pouring shown); the scene cuts to a different camera angle or setting mid-procedure; the lighting on the flask changes suddenly and without explanation from one frame to the next.
level_2: The flask, pipette, or burette shifts position or rotates in a way that breaks continuity (for example the EDTA burette jumps from one side of the flask to the other); an object visibly bends, warps, or fractures in an impossible way, or liquid appears to defy gravity (floating, flowing upward, or hanging in place); the swirling motion reverses direction abruptly or stops instantly without slowing; the shadow beneath the flask points in a different direction than in earlier frames with no corresponding change in the scene to explain it.
level_3: The pipette stays close to the flask throughout the transfer, the EDTA burette stays positioned above the flask during titration, and the swirling proceeds in one rotational direction without reversing; no object appears or disappears without a visible cause, and there is no abrupt camera cut; a hand briefly passes in front of the flask during pipetting but the flask is fully visible again right after.
level_4: The pipette tip is visible entering the flask, indicator droplets are visible traveling from the vial to the flask, and the EDTA stream is visible traveling from the burette tip to the liquid surface without being blocked from view; the swirling stays smooth and centered on the same axis; the light source and the flask's cast shadow keep the same direction and brightness across the whole sequence; the pipette, flask, and burette keep the same relative positions on screen throughout, without unexplained drifting or camera zoom.
level_5: The pipette's insertion path, the arc of the indicator droplets from vial to flask, and the EDTA stream from burette tip to liquid surface are each traceable continuously from frame to frame with no gap; the swirling rotates at a steady rate around a fixed center for its whole duration; the direction and brightness of light and shadow on the flask stay identical from the first frame to the last; the camera position and framing never change, and the entire procedure plays as one continuous shot with no cuts or viewpoint shifts.