This Assessment Activity will start with observations of kitchen reactions and identifying which type of reaction is occurring. Kaiako will assist ākonga to relate each reaction in the kitchen to the reaction modelled in the laboratory. They will use their observations and the equations to show understanding of conservation of mass in modelled reactions, linked to the context of a reaction in the kitchen. 

The chemistry of many examples in the context of the kitchen can be inaccessible to ākonga, and are above Level 6 of The New Zealand Curriculum: Learning Media, Ministry of Education, 2007. Additional resources and kaiako scaffolding may be required to help ākonga see the relationship between each reaction modelled in the laboratory and the context of a kitchen. 

Practical work 

It is expected that ākonga have already carried out practical investigations and modelled experiments during teaching and learning. However, this is not a requirement. Creating a table for ākonga may help them organise information collected from laboratory or kitchen-based investigations and research. The table could provide space for each observation, and space to organise information by reaction type.  

Ākonga are being assessed on their ability to identify and explain reactions in context, using modelled reactions and chemical equations used in the laboratory.  

To check for safe practice protocols when ākonga are engaging in chemistry practical activities in the laboratory, refer to the Safety and Science/Pūtaiao: Guidance for Schools and Kura (newzealandcurriculum.tahurangi.education.govt.nz) and the Biolab Sourcebook 2nd Edition, A manual for science teachers and technicians (crescendo.co.nz)

Review food safety policies and procedures (Ministry of Education)

Food safety resources for teachers (Ministry for Primary Industries)

Resources 

When observing reactions in the kitchen, ākonga should be able to categorise them to be one of the five reaction types listed in Explanatory Note 2 of the Achievement Standard. These reactions will have been modelled in laboratory investigations with support from kaiako. Guidance will be needed when ākonga carry out and learn about diagnostic tests that identify reactants or products. 

An example of application of the assessment to the kitchen context for “hokey pokey” is provided below. This would provide assessment of one reaction type. Two further reaction types in a kitchen context are required for the full assessment. For each context where ākonga consider chemical reactions that occur in the kitchen, ākonga will identify the predictable pattern of the chemical reaction type as one of: 

• neutralisation 
• combustion 
• precipitation 
• combination 
• decomposition. 

Ākonga should use observations to explain why they chose this reaction type. To do this ākonga may: 

• link observations to the reactant or products 
• link observations to the predictable pattern of the reaction type 
• explain how the recorded observations match the changes shown in the balanced chemical equation provided, by referring to identification tests. 

To show understanding of conservation of mass, ākonga could use the balanced chemical equation of the laboratory model, and refer to the relationship between reactants and products. Ākonga should discuss:  

• the type of atoms or ions 
• the number of atoms or ions of each type (this can be shown numerically or by using a diagram)  
• what happens to the atoms or ions during the reaction.  

For higher levels of achievement, ākonga should discuss the implications of conservation of mass applied to chemical reactions in the kitchen. This may refer to a reactant or product of this reaction building up or reacting in a predictable way. Ākonga could refer to state, quantity, location, physical properties, or chemical properties of the reactant or product. They could show an understanding of the balanced chemical equation of the laboratory model to support their answer. A teaching and learning programme should cover examples of all five reaction types. Three relevant contextual examples should be chosen for assessment. One example is given below. 

An example of a chemical reaction that occurs in the kitchen is using baking soda during the making of hokey pokey. When making hokey pokey, the hot toffee will puff up when baking soda is added. This same reaction is modelled in the laboratory when calcium carbonate is heated in a boiling tube. The gas given off can be bubbled through limewater turning the limewater solution from clear to cloudy. The balanced chemical equation and diagram of the laboratory model are shown below.  

[ Image Resource ]

• Caption: Limewater test.
• File URL: https://ncea-live-3-storagestack-53q-assetstorages3bucket-2o21xte0r81u.s3.amazonaws.com/s3fs-public/2025-01/Limewater%20test.JPG?VersionId=apZJ0_IkpSNq7ZvglTF0j1DFhCjYMHzQ
• File Size: 27KB
• File Extension: jpg
• Description:

[ Image Resource ]

• Caption: Equation for decomposition of calcium carbonate.
• File URL: https://ncea-live-3-storagestack-53q-assetstorages3bucket-2o21xte0r81u.s3.amazonaws.com/s3fs-public/2025-01/Equation%20for%20decomposition%20of%20calcium%20carbonate.JPG?VersionId=DyHqeLrgwWxvvuOC1bsss7FLMo3Do55u
• File Size: 10KB
• File Extension: jpg
• Description:

Ākonga may be asked about the consequences for the hokey pokey product if the amount of the baking soda reactant was increased. In response ākonga may: 

• give implications for the hokey pokey of increasing the baking soda reactant, by referring to the balanced chemical equation of the laboratory model 
• discuss how the results can be predicted and observed using the laboratory model to support their answer. 

Ākonga should be provided with information that is sufficient for them to meet all achievement levels of the Achievement Standard. This may be extended to provision of solubility tables and descriptions of common secondary chemical tests, which may include Universal Indicator for acids and bases, cobalt chloride paper for water, or lime water for CO2 identification. This information may also be provided in classroom teaching and learning, and notes can be used by ākonga in the assessment period. 

Cultural safety 

Inclusive language, appropriate graphics, and other aspects of cultural safety will need to be taught and monitored. This will ensure all ākonga and whānau are kept culturally safe. 

Assessment  

This Assessment Activity will be the culmination of approximately eight weeks of teaching and learning. Learning and assessment can be woven together. Ākonga can gather evidence during the teaching and learning, which can be used for the Assessment Activity. The Assessment Activity is expected to take four hours. These hours can be spread out over the teaching and learning program and do not need to be consecutive. 

Practical investigations and recording of observations are not assessed. The observations may be compiled in a portfolio to be used in the Assessment Activity. The time spent in collection and recording of observations is not included in the recommended timeframe. 

The collection and recording of observations do not need to happen consecutively. These can occur throughout the teaching and learning programme. Assessment of the range of reaction types may take place following teaching and learning of each reaction type, or in one assessment period.