# Marking Guide: Enthalpy Changes and Calorimetry

## Task

Students present a labelled model or report on enthalpy changes and calorimetry. The work must define enthalpy, apply Q = mcΔt to heat transfer data, use calorimetry data to determine enthalpy change, and communicate results using correct ΔH notation.

## Curriculum alignment

- 30-A1.3k: define enthalpy and molar enthalpy for chemical reactions ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23636), [Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23636))
- 30-A1.1k: recall the application of Q = mcΔt to the analysis of heat transfer ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634), [Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634))
- 30-A1.8k: use calorimetry data to determine the enthalpy changes in chemical reactions ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641))
- 30-A1.5k: use and interpret ΔH notation to communicate and calculate energy changes in chemical reactions ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23638))
- 30-A1.3s: analyze data and apply mathematical and conceptual models to develop and assess possible solutions ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23648))

## Rubric

| Criterion | Beginning | Developing | Proficient | Exemplary |
|---|---|---|---|---|
| Definition of enthalpy and molar enthalpy ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23636), [Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23636)) | Enthalpy is mentioned but not defined, or the definition is incorrect. | Enthalpy is defined but molar enthalpy is missing or vague. | Enthalpy and molar enthalpy are both defined accurately, using correct units. | Definitions are precise, distinguish enthalpy from molar enthalpy clearly, and connect to the reaction studied. |
| Application of Q = mcΔt ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634), [Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634)) | Formula is missing, misapplied, or variables are undefined. | Formula is applied with minor errors in substitution or units. | Formula is applied correctly with all variables identified and units shown. | Formula is applied correctly and the student explains the physical meaning of each term. |
| Use of calorimetry data to determine enthalpy change ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641)) | Calorimetry data is presented but no enthalpy change is calculated. | Enthalpy change is calculated but contains errors in logic or arithmetic. | Enthalpy change is calculated correctly from calorimetry data, with a clear method. | Calculation is correct, method is clearly explained, and sources of experimental error are identified. |
| ΔH notation and communication of energy change ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23638), [Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23648)) | ΔH notation is absent or used incorrectly. | ΔH notation appears but sign convention or units are inconsistent. | ΔH notation is used correctly, with correct sign and units, to communicate the energy change. | ΔH notation is used correctly and the report analyzes the result, such as comparing it to an accepted value or energy diagram. |

## Scoring

Assign each criterion a level: Beginning (1 point), Developing (2 points), Proficient (3 points), or Exemplary (4 points). Sum the four scores for a total out of 16.

- 4 to 7: Beginning overall
- 8 to 10: Developing overall
- 11 to 13: Proficient overall
- 14 to 16: Exemplary overall

A student who scores Beginning on the calorimetry calculation criterion should not receive an overall Exemplary result, regardless of total score, since correct use of calorimetry data ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641)) is central to the task.

## Notes for the teacher

- Confirm that the reported ΔH carries the correct sign for the reaction type (exothermic versus endothermic) before scoring the notation criterion.
- Students should be able to use calorimetry data to determine enthalpy changes and apply Q = mcΔt to analyze heat transfer in chemical reactions.
- Reference [Resource](https://goa-cc-uat-aili-app-001.azurewebsites.net/library/resource/9ykNTynh306g6EnZlkTITQ) or [Resource](https://goa-cc-uat-aili-app-001.azurewebsites.net/library/resource/0uxhxD914kqzmssVwCK4tg) procedures when checking whether a student's described method matches an actual calorimetry setup.
- Where a report cites an accepted literature value for comparison, treat this as evidence toward the Exemplary level on the ΔH notation criterion, not as a separate requirement.

---
*AILI marking guide · language en · model claude-sonnet-5 · generated 2026-09-17 · id 16af1f9a-eb97-4d80-88d4-882cf7c79007*

### Sources

- node:n1: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23636)
- node:n2: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634)
- node:n3: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641)
- node:n4: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23647)
- node:n5: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634)
- node:n6: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23636)
- resource:r1: Resources › type#activity › SCN3796 (https://goa-cc-uat-aili-app-001.azurewebsites.net/library/resource/9ykNTynh306g6EnZlkTITQ)
- node:n7: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23638)
- node:n8: Chemistry › Chemistry (20, 30) › Chemistry 30 › Unit A: Thermochemical Changes › General Outcome 1 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23648)
- resource:r2: Resources › type#activity › SCN3796 (https://goa-cc-uat-aili-app-001.azurewebsites.net/library/resource/0uxhxD914kqzmssVwCK4tg)