This packet is everything a parent or guide needs to assess Unit 05 at home — learning targets, the answers that count as correct, the mastery rubric, calibration examples, and a clipboard score sheet. No multiple-choice test: the student shows mastery by measuring heat in a calorimeter and computing a defensible enthalpy change.
By the end of the Thermochemistry unit, a student should be able to:
Six criteria, each judged Not yet / Approaching / Mastered (Page 3).
Measure a temperature change; compute the heat of reaction.
The student explains exo- vs endothermic by sign (Page 4).
Temperatures, calculation, and ΔH kept distinct.
You are making a decision, not adding up points. For each criterion, decide whether the work is Not yet, Approaching, or Mastered — the column language tells you which. A criterion counts as mastered only when the student can both take the measurement and defend the sign and the number. A student carries three tokens per term; one token buys a re-do of one criterion on another day, so a single bad afternoon never sinks the unit.
Accept any answer in the synonyms column — they are pre-approved as equivalent. The third column flags the confusions that look close but are not yet, so you can coach precisely.
| Canonical answer | Accepted synonyms | Common confusion / discriminator |
|---|---|---|
| Energy & sign | ||
| Enthalpy (ΔH) | heat of reaction | Negative = exothermic (releases), positive = endothermic (absorbs) |
| Exothermic | heat-releasing | ΔH < 0; surroundings warm up |
| Endothermic | heat-absorbing | ΔH > 0; surroundings cool down |
| System vs surroundings | reaction vs everything else | Heat lost by the system is gained by the surroundings — opposite signs |
| Measuring & combining | ||
| Calorimetry | q = mcΔT | Measures heat by temperature change; watch the units |
| Specific heat (c) | heat capacity per gram | Property of the substance; water's is notably high |
| Hess's law | enthalpy additivity | Flip a reaction → flip ΔH sign; scale a reaction → scale ΔH |
| Bond energy | bond enthalpy | ΔH ≈ bonds broken − bonds formed |
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Enthalpy & energy diagrams | Confuses exothermic and endothermic or their signs. | Labels ΔH signs but misreads energy diagrams. | Interprets energy diagrams and assigns ΔH signs, relating them to bond making and breaking. |
| Calorimetry calculations | Cannot set up q = mcΔT. | Uses the equation but mishandles units or the system–surroundings sign. | Calculates heat transfer correctly and assigns it to the reaction with the right sign. |
| Hess's law | Adds reactions without adjusting their enthalpies. | Manipulates equations but forgets to flip or scale ΔH. | Combines, reverses, and scales reactions to find an overall ΔH consistently. |
| Bond energy estimates | Ignores bonds when reasoning about energy. | Sums bond energies but mixes up bonds broken vs. formed. | Estimates ΔH from bond energies, correctly subtracting bonds formed from bonds broken. |
| Lab technique (calorimetry) | Loses heat to the surroundings and ignores it. | Runs the calorimeter but records temperature carelessly. | Measures ΔT precisely, accounts for heat loss, and computes a defensible ΔH. |
| Integration (cross-domain) | Treats the science as isolated facts; makes no cross-domain connection. | Names a link to history, reading, or writing but cannot defend why it matters. | Connects the unit to its anchor across History · Reading · Writing (plus chosen electives) and defends why the connection matters. |
The split between Approaching and Mastered is the sign is physical: a warming cup means the reaction released heat (ΔH < 0). Ask “did the thermometer go up or down, and does your sign match?”
Read these before you grade. They show what Mastered and Not yet actually sound like, plus the edge cases where you should coach rather than decide on the spot.
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Enthalpy & energy diagrams | NY / Appr / Mast | |
| 2 | Calorimetry calculations | NY / Appr / Mast | |
| 3 | Hess's law | NY / Appr / Mast | |
| 4 | Bond energy estimates | NY / Appr / Mast | |
| 5 | Lab technique (calorimetry) | NY / Appr / Mast | |
| 6 | Integration (cross-domain) | NY / Appr / Mast |
☐ No ☐ Yes — for criterion: __________ Tokens remaining: ☐ 3 ☐ 2 ☐ 1 ☐ 0
NY = Not yet · Appr = Approaching · Mast = Mastered · Unsure between two levels? Circle the lower one and note what a re-do would need.