AP Chemistry Unit 8 — Acids and Bases — your whole-unit review

Card 1/28 · ADJUDICATIONS §E item 1 · §E-S07b.4

Keep the binary-acid trend atoms assessed?

The course says: why HI is a stronger acid than HF (bond strength wins down a group) is taught AND assessed (ACB-070/071) — on the Learning Objective's licence, not the EK's enumerated list. You approved this on 2026-08-03; your bias-to-the-exam directive carries it independently (binary-acid comparisons are standard AP items).

The honest cost, corrected on the record: "demote to enrichment" is no longer one tap. S07's L11 factor table and two checks now assess this content, so a demotion would re-scope a third atom (ACB-072) — a register decision, not a wording change.

My recommendation: Confirm — kept assessed.

Card 2/28 · ADJUDICATIONS §E item 2 · 05_operator_adoption D6

Keep the weak-base mirror lessons as full per-direction atoms?

The course says: every weak-acid routine has a full mirror lesson for the base direction — same frame, one change, with the extra pOH→pH step treated as the separately failable behaviour. This was your coarseness call (approved 2026-08-03); the register stands at 137 atoms on it.

Why it held up: the blueprints built each mirror as a true minimal-difference pair, and the mirrors carried their own wrong-paths (swapped pH/pOH, Ka-for-Kb) through QA.

My recommendation: Keep the mirrors; one tap reopens a merge if mastery data ever says they are redundant.

Card 3/28 · ADJUDICATIONS §E item 3 · 05_operator_adoption catch 6

FYI: a register edit run in your name — the U7 pH-observable handoff is now anchored

The course says: Unit 7 deferred "pH as a Le Châtelier observable" to Unit 8, but neither register carried an anchor — the handoff existed only in a decision note. Executed: the two pH-and-solubility atoms (ACB-133/134) now list EQM-073 as a prerequisite, and S15 treats pH-as-observable as U7 retrieval, never re-taught.

Card 4/28 · ADJUDICATIONS §E item 4 · §B4 · updates your open U7 card

Acetic acid prints as CH₃COOH on every U8 surface — settle the formula style course-wide?

The course says: U8 writes the structural form CH₃COOH everywhere (never HC₂H₃O₂). Your U7 formula-style card was still open when U8 built, so this card updates it with the U8 usage.

Why: U8 lives on conjugate pairs — the structural form shows which proton leaves (the COOH one), which the condensed form hides.

Cost of flipping: one tap; the engine re-prints every surface either way.

My recommendation: CH₃COOH course-wide.

Card 5/28 · ADJUDICATIONS §S03-7

The very-dilute boundary stays untaught — park it as an enrichment candidate?

The headache: what is the pH of 1×10⁻⁸ M HCl? The naive routine answers 8 — an acid that reads as a base. The honest answer needs water's own autoionization, machinery the unit never otherwise needs.

The course says: the case is PARKED, never taught, never assessed (§S03-7). The CED does not require it.

My recommendation: Park it as an enrichment candidate.

Card 6/28 · ADJUDICATIONS §S14-6

Add an "effective buffer range is pKa ± 1" atom, or keep it out?

The course says: the ±1 rule of thumb stays OUT of Unit 8. The register's own wording at ACB-093 ("a significant concentration of both members") already covers the teaching need.

Why: the CED never names the ±1 rule; adding it is a register insertion near ACB-093 — your call only, so the build did not make it.

My recommendation: Keep it out.

Card 7/28 · ADJUDICATIONS §S04-1

FYI: S04's lesson order was re-sequenced in your name

The course says: the weak-base arc now runs unbroken (L08–L12) and the particulate pair closes the sequence (L13–L14) — register rev 1.6. The drafted order interleaved them.

Why: an unbroken arc keeps each mirror beside its acid twin; the particulate pair needs both arcs taught first.

Card 8/28 · ADJUDICATIONS §S05-1/2

FYI: the register's worked-example lane for the weak-acid pH routine now names benzoic acid

The course says: ACB-050's example lane carries a note (rev 1.6) naming benzoic acid as the worked system; the drafted pH value 1.94 was flagged and never printed anywhere.

Card 9/28 · ADJUDICATIONS §B8

Confirm the 22 registered misconceptions?

The course says: misconception claim-items run only on a registered, sourced belief. Rev 1.6 registers 22 entries on 20 atoms — registration, not invention; every entry sourced to the chemistry-education catalogue.

Orgill & Sutherland 2008 (buffers) · McClary & Talanquer 2011 (acid-strength heuristics) · Sheppard 2006 (titrations and indicators) · Raviolo 2001 and Önder & Geban 2006 (solubility) · Schmidt (neutralization) · the standard water-chemistry rows

Why: multi-site beliefs register once with licensed confrontation sites (strong ≠ concentrated; neutral is not always pH 7). Claim items use reported speech; the whole-unit key tally is 8 Yes / 14 No including gates — no guaranteed-No shape anywhere.

My recommendation: Confirm all 22.

Card 15/28 · ADJUDICATIONS §E-S11b.7 · REVIEW_LESSON_U8-S11 row 15

The indicator coin narrows the register's wording to colour — harmonise or leave?

The coin line: the two indicator forms "show different colors"
The register (ACB-097), echoed by the note and two feedback lines: "different properties, such as color"

Why it was left: the coin narrows honestly to the colour case; grep proves no later surface keys on a non-colour property, so the coin out-runs nothing. A register re-scope is yours, not a seat's.

My recommendation: Leave both wordings as they stand.

Card 12/28 · ADJUDICATIONS §B5

Eleven photo-real hooks shipped — keep all, or strike any back to drawn figures?

The course says: each photo carries a felt scene and no data; everything exact stays a drawn figure (your 2 Oct decision). All eleven are independently QC'd on the rendered page and file-referenced, never embedded. S10 runs photo-free (no honest meter asset exists anywhere).

My recommendation: Keep all eleven.

Card 11/28 · ADJUDICATIONS §S15-7 · §E-S15.4

FYI: the milk-of-magnesia photo shipped only after its medical-wording gate was satisfied

The course says: the render was GATED on the subject-expert's medical-wording line (the U7 barium-meal pattern). The gate bit for real: the lesson's "mostly Mg(OH)₂" came out first (real milk of magnesia is ≈8% Mg(OH)₂), and the caption and alt name a suspension — zero medical words, no pH value, no strong-base label.

Standing open card · gains U8 evidence · qa/PHOTO_QC_U8-S02..S15

Your photo-QC sharpness rule keeps failing good photos — six more data points

The headache: the QC checklist's SHARP_NO_DOF axis demands everything in frame pin-sharp — no depth-of-field blur anywhere. Real bench and kitchen photos compose with soft backgrounds.

The U8 evidence (six counted data points onto your open card): every photo passed every content check; the independent QC's overall verdict failed on sharpness ALONE again and again — kitchen shelf, both S03 bottles, both shared S04 assets, the pool strip, the cabbage trio, the buret bench (the 4th counted point), the twin flasks (5th) and the milk of magnesia (6th). The one outright pass: the runner photo. No take was ever burned on sharpness alone (the depth-composed prompt pattern is the standing workaround); all renders shipped and read well.

My recommendation: relax the axis to "subject sharp; background softness allowed".

Card 17/28 · ADJUDICATIONS §E-S12b.2

The buffer-check table draws its deciding question at the foot — re-render it at the head?

The course says: the S12 comparison table draws its first-ask question as a bold line at the FOOT of the table. The shipped fix is one caption sentence: "The bold line at the foot comes first in use: ask its question before you use any row."

Why the engine change was not taken: moving the line to the head re-renders a shared figure family across closed sequences — a blast radius one caption sentence avoids.

My recommendation: the caption stands.

Card 18/28 · ADJUDICATIONS §E-S13b.6

Two figure label-size floors now exist — one law or two?

Titration-curve family: smallest on-figure labels ≈ 10.5 px (its measured norm; readable in both colour schemes)
Equation-stack family: a 13 px floor

The question: does the course adopt one floor for all figure families, or keep per-family measured norms?

Cost of one law at 13 px: the titration-curve family re-renders across closed sequences.

My recommendation: per-family norms, each measured on its own renders.

Card 26/28 · UNIT8_VERIFICATION Part 2b · §E-S09b queue

Adopt a 15 px legend floor for the particle boxes — and reflow about 30 shipped renders?

The course says: a proposed floor (particle-box legend text never below 15 px) is argued and the refusal mechanism is already built engine-side. Applying it to U8 would REFUSE 4 shipped S04 canvases and reflow ~30 renders across closed sequences — a dedicated re-open round.

My recommendation: queue it for the U9 engine; U8 ships as it stands.

Card 13/28 · ADJUDICATIONS §E-S10b.4 · REVIEW_LESSON_U8-S10 row 3

S10 L01's forest close says the answer "is taught just ahead" — keep it, or go meta-free?

Shipped (the blueprint's own planned line): "Which way the mixing ratio nudges the pH inside that neighborhood is taught just ahead."
One-tap alternative: "…inside that neighborhood comes next."

Why it was left: it is the multivariable spine's handover line, previewing only that the question has an answer; the reviewer declined to override a planned forest line on style.

My recommendation: keep the shipped line.

Card 14/28 · ADJUDICATIONS §E-S10b.4 · REVIEW_LESSON_U8-S10 row 12

S10 L04's worked lines re-print pKa values without "at 25 °C" — add it at article grain?

The course says: the temperature law binds stems and tables, and it holds 28/28 there. L04's article lines ("The formic buffer lands at pH = 3.75 + log(2)…") re-run values the same scene already anchored WITH the temperature, so the reviewer ruled them a worked restatement and left them.

One tap: append "at 25 °C" at the article grain too — the letter of the law on every print.

My recommendation: leave the stem/table grain.

Card 16/28 · ADJUDICATIONS §E-S11b.7 · REVIEW_LESSON_U8-S11 row 17

The unit's one all-caps word: "A pH BELOW the pKa" — keep the shout or lower-case it?

The course says: one feedback line in S11 L01 shouts "BELOW" — the sequence's only all-caps word. It was left because the emphasis aids the exact correction the student needs there (they compared the wrong way round).

My recommendation: keep the emphasis.

Card 19/28 · ADJUDICATIONS §E-S13b.6 · REVIEW_LESSON_U8-S13 row L2

The curve-sketch lines place the strong–strong landmark "at 7" without "at 25 °C" — add the letter of the law?

The course says: S13 L10 teaches curve sketching with landmark placements ("place the equivalence pH: at 7 for strong–strong…"). Every PRECISE pH-7.00 claim in the unit carries "at 25 °C"; these sketch landmarks do not, and the reviewer ruled them placements, not claims.

One tap: append "— all at 25 °C" to the landmark triple.

My recommendation: leave the landmark grain.

Card 20/28 · ADJUDICATIONS §E-S15.5 · REVIEW_ACCURACY_U8-S15 row 3

"A few drops" of acid visibly shrink the solid in the S15 scene — keep the scene grain?

The course says: S15's opening scene has the chemist stirring "a few drops of dilute strong acid" into the jars and seeing the leftover solid shrink. Direction and mechanism are exactly true; the magnitude is schematic — a few drops dissolve roughly 1–40 mg, a real shrink you would not SEE at bench grain. No item keys on visibility.

One tap for bench-literal truth: "stirs in some dilute strong acid" (the quantifier moves, two surfaces; nothing else is disturbed).

My recommendation: the scene stands.

Card 21/28 · ADJUDICATIONS §E-S15b.3 · REVIEW_LESSON_U8-S15 row L7

The S15 routine's step 2 says the pH change "adds" ions — align it to its own case lines?

Shipped step 2: "Second, name what the pH change adds to the solution: H₃O⁺ when the chemist lowers the pH, OH⁻ when the chemist raises it."
The case lines' clean form: "the lowered pH means added H₃O⁺"
One-tap alternative: "Second, name what arrives with the pH change: …"

Why it was left: the wording is the approved blueprint's own, and your quantity-never-acts rule has the chemist doing the lowering; "adds" gives a quantity-event a verb at the boundary of the rule.

My recommendation: keep the shipped step; it is the blueprint's own line.

Card 27/28 · UNIT8_VERIFICATION Part 2c · §E-V.1(a) · executed

Done under warrant: one British spelling inside a sealed test stem is fixed — ratify?

The course says: the test's Q01 stem read "the Brønsted-Lowry behaviour available to…" — an authored stem in a US-spelling course, and a sealed-bundle surface. The fix ran under the sealed-bundle law: sealed copy preserved, re-cut, the leaf diff exactly the one stem, one-item cold re-read PASS (qa/APPLICATION_U8-V.md).

Card 28/28 · UNIT8_VERIFICATION Part 3 · §E-V.1(b) · executed

Done under warrant: six caption/alt em dashes written before the scope ruling are split — ratify?

The course says: a late ruling put figure captions and alt texts inside the em-dash scope (the feedback-frame dash stays the only licence). Six residues predated it: captions at S03 L07, S04 ×2, S06 L01, S11 L04 and the S12 L09 alt. All six now read as two sentences; the owning bundles re-cut byte-identical (captions are article furniture, never bundle-resident).

Optional rider (uncounted) · ADJUDICATIONS §E-S09b pens

Restore the conventional sprint-blood claim?

Shipped (the safer wording): "…a blood sample taken right after the race shows a pH still close to 7.4 — only a little below its pre-race value." + "A healthy body keeps its blood pH between 7.35 and 7.45."
The conventional claim, cut as not strictly true: the post-race pH is "the same as before the race"

My recommendation: keep the safer wording.

Optional rider (uncounted) · ADJUDICATIONS §E-S09b pens · REVIEW_LESSON_U8-S09 §3

Keep the deferral line's "settles at"?

The course says: S09 L02 defers the buffer-pH question with "Why a given buffer settles at its particular pH needs ideas that this unit teaches later." The reviewer flagged "settles at" as a one-tap alternative if you read it as giving the buffer agency; it ships as the single instance course-wide.

My recommendation: keep "settles at".

Card 10/28 · ADJUDICATIONS §S02-1 · §B3

Ratify the pH-precision convention as course law?

The course says: the number of significant figures in a concentration sets the number of DECIMAL PLACES in its pH, and the inverse read runs the same rule backwards. It is taught inside the pH routine itself (register scope note rev 1.6), and every stem states its required precision.

Why: it is the convention AP scoring actually uses; one rule covers every pH, pOH and pKa lane in the unit.

My recommendation: Ratify.

Card 22/28 · ADJUDICATIONS §E-P-pre · REVIEW_PRACTICE_U8 conversion 1

Practice: the real 2021 draw-a-Lewis-diagram part became describe-in-words — approve?

Released: "In the box below, complete the Lewis electron-dot diagram for HCOOH. Show all bonding and nonbonding valence electrons." (with the printed skeleton)
Shipped: the prompt quotes the exam's ask and skeleton, then asks the student to STATE which carbon–oxygen bond is double, what every other bond is, and the nonbonding pairs per atom

Why: the platform has no draw input; the rubric keeps the Scoring Guide's one point as the described features. Same conversion class you approved at U5-P2 and U7-P1(c).

My recommendation: Approve.

Card 23/28 · ADJUDICATIONS §E-P-pre · REVIEW_PRACTICE_U8 conversion 2

Practice: the same question's pressure graph became one stated datum — approve?

Released: "…the total pressure is monitored, as shown in the graph above." (the figure's only printed value is the 24 atm plateau — verified on the booklet page)
Shipped: the prompt states the graph's one read: "it rises from 0 atm and levels off at 24 atm, where it stays"

Why: no course figure family draws a pressure–time curve, and inventing sampled points a released graph never printed would fabricate data. Both scored skills (halving the total; PV = nRT) survive whole; the plateau read is not separately scored.

My recommendation: Approve.

Card 24/28 · ADJUDICATIONS §E-P-pre · the CARD-ASSESS-1 family

When a real question is split across units, is the ledger's grain the part or the question?

The case: practice uses 2025 Q2 parts A and B verbatim. Parts C and D were deliberately NOT consumed (C is kinetics, fenced; D is the Lewis-figure class). The usage ledger needs your standing rule: may a later unit's assessment use C/D, or does any use spend the whole question?

Why it matters: released AP questions are a finite resource; part-level grain roughly doubles what the later units can draw on.

My recommendation: part-level grain — C and D stay usable.

Standing open card (your U7 queue) · gains U8 counted evidence · UNIT8_VERIFICATION Part 2i

The house feedback opener presumes an error path — hold the frame, or reframe course-wide?

The course says: every wrong option's feedback opens "This option is wrong — you …" — the contracted house form, shipped on every unit since U1. The vault's own rule ("option feedback explains, never presumes") names this exact frame as its origin case.

The U8 counted evidence for your open card: the "— you" opener ships ×529 in U8 (any "This option is wrong —" form ×941); in S02, 61 of 108 wrong-feedbacks carry presumptive clauses; in S07, 31 of 114.

Cost of reframing: a mid-course voice change desyncs eight shipped units; the retrofit is a course-wide re-open. The unilateral reframe was declined twice on that precedent.

My recommendation: hold the house frame; your one tap settles it course-wide either way (the vault records the exemption or the retrofit).

FYI (uncounted) · UNIT8_VERIFICATION Part 2p · §E-V.3

FYI: the build's tail is not yet committed — let the automatic backup run

The course says: per your mandate, the build committed nothing. Everything from Saturday ~18:00 onward — the S13/S14/S15 closes, G5/G6, practice, the test and every close-out record — lives only on the working tree (~107 uncommitted paths). The last automatic backup ran at 18:00 on 10 Oct; until the next one sweeps the tree, a disk fault loses the build's tail.

One disclosure rides this: the after-18:00 "nothing else was touched" proofs ran at reconstruction grain rather than git grain (there was no commit to diff against) — ratified on the record.

Card 25/28 · UNIT8_VERIFICATION Part 2a

U7 maintenance: one shipped U7 table draws its caption inside the scroll strip — fix sealed U7, or leave it?

The course says: U7's table renderer puts the caption INSIDE the horizontal scroll wrapper — the class U8's engine refuses by design. Measured read-only against U7's own figures: 22 table figures, 13 captioned, exactly one wider than the 408 px wrapper (the U7 practice page, est. 435 px; its caption is one short sentence, so the visible harm is low). U7 is sealed; nothing was edited.

My recommendation: leave U7; the U9 engine inherits the fix.

Whole unit · 15 sequences · 6 gates · practice · test

Unit 8 as a whole

137 lessons · 705 questions · 296 figures · zero key clashes · zero ship-gates. Open the course page in the next tab and dip in anywhere.