# Marking Guide: Enthalpy Changes and Calorimetry

## Task

Students present a labelled model or report on enthalpy changes and calorimetry. The submission must define enthalpy, apply the relationship Q = mcΔt, and use calorimetry data to determine the enthalpy change of a chemical reaction, with calculations and supporting diagrams or data tables clearly labelled.

## 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))
- 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))
- 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))
- General Outcome 1: determine and interpret energy changes in chemical reactions ([Topic](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23633))

## Rubric

| Criterion | Beginning | Developing | Proficient | Exemplary |
|---|---|---|---|---|
| Enthalpy concept and ΔH notation | States enthalpy is related to heat but gives no definition; ΔH notation absent or incorrect ([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/23638)). | Defines enthalpy with minor inaccuracy; uses ΔH notation inconsistently across the report ([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/23638)). | Correctly defines enthalpy and molar enthalpy; applies ΔH notation consistently and correctly ([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/23638)). | Defines enthalpy precisely and explains molar enthalpy in context; ΔH notation used correctly with signs and units throughout ([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/23638)). |
| Application of Q = mcΔt | Formula stated but not applied, or applied with major errors in variables or units ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634)). | Applies Q = mcΔt with one significant error in substitution, units, or arithmetic ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634)). | Correctly applies Q = mcΔt with proper units and accurate arithmetic throughout ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634)). | Applies Q = mcΔt accurately and explains the physical meaning of each variable within the calorimetry context ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23634)). |
| Use of calorimetry data to determine enthalpy change | Calorimetry data present but not connected to an enthalpy calculation ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641)). | Uses calorimetry data to calculate enthalpy change with incomplete reasoning or an unaddressed error source ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641)). | Uses calorimetry data correctly to determine enthalpy change, with reasoning that matches procedures such as those in a calorimetry lab ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641), [Resource](https://goa-cc-uat-aili-app-001.azurewebsites.net/library/resource/9ykNTynh306g6EnZlkTITQ), [Resource](https://goa-cc-uat-aili-app-001.azurewebsites.net/library/resource/0uxhxD914kqzmssVwCK4tg)). | Uses calorimetry data to determine enthalpy change accurately and evaluates sources of experimental error affecting the result ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23641), [Resource](https://goa-cc-uat-aili-app-001.azurewebsites.net/library/resource/0uxhxD914kqzmssVwCK4tg)). |
| Data analysis and presentation | Data or diagrams included with little organization; labels missing or unclear ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23648)). | Data presented in tables or diagrams with basic organization; some labels missing ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23648)). | Data and diagrams are organized, labelled, and support the calculations presented ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23648)). | Data and diagrams are organized, fully labelled, and used to assess the validity of the reported energy change ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23648)). |

## 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. Convert to a percentage grade if required by school reporting practice, or report the total alongside the level descriptors so students can see strengths and gaps by criterion.

## Notes for the teacher

- Apply the calorimetry criterion consistently whether students conduct a hands-on investigation, such as those described in [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), or analyze provided calorimetry data.
- Distinguish between a student who applies Q = mcΔt correctly but fails to connect the result to enthalpy change (score lower on the third criterion) and one who makes both connections.
- Award Exemplary on the enthalpy notation criterion only when sign conventions for exothermic and endothermic processes are used correctly, not merely present.
- When moderating across a class set, review a sample of Proficient and Exemplary submissions together to confirm a shared standard before finalizing grades.

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*AILI marking guide · language en · model claude-sonnet-5 · generated 2026-09-17 · id 2bf8d0c3-57b7-4982-a14a-de7524105e42*

### 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/23634)
- 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/23636)
- 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/23638)
- 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 (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/23633)
- 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)