Clarification details
Updated December 2021. This document has been created to address issues that have arisen from moderation.
Achievement standard requirements
The investigation involves the collection of primary data. The assessment needs to give learners the opportunity to collect the primary data following a given identification procedure.
A purpose/context for the investigation is required for learners to describe/explain/discuss the significance of an identified species.
The chemical species should be from a single sample. These species could be identified from separate solutions so long as the solutions originated from a single sample. Two chemical species need to be identified to meet the standard.
Making judgements
For all levels of achievement, learners need to collect primary data using a supplied identification procedure. The primary data is then used to identify the species by matching the primary data to the procedure used. Learners then need to use the findings from the investigation to identify the compound present in the sample. The significance of an identified chemical species for people and/or the environment needs to be described relative to the purpose/context of the investigation.
In addition, Merit requires learners to explain the identification of the species by linking the primary data to the procedure used and writing equations for all the changes that occurred during the identification procedure. Identification of ions in solution will require ionic equations for the formation of precipitates and complex ion equations where appropriate. Identification of functional groups in organic molecules will require full structural formulae of organic molecules to be shown in equations. The significance of an identified species for people and/or the environment needs to be explained relative to the purpose/context of the investigation.
In addition, Excellence requires learners to justify the identification of the chemical species. The justification needs to link supplied secondary data and chemical principles to the reactions that occurred during the analysis of the unknown sample. The significance of an identified chemical species for people and/or the environment needs to be discussed relative to the purpose/context of the investigation.