Clarification details
Updated April 2016.
This standard involves demonstrating an understanding of oxidation-reduction.
The purpose of clarifications
We create clarification documents to help people understand the current requirements of achievement standards. Clarifications do not introduce new criteria, change the intent of the standard, or change what we expect from assessment.
These documents unpack and explain the language and intent of the standard so people interpret and apply the standard consistently. We provide examples or guidance as illustrations only. They are not prescriptions or requirements.
For official requirements, always refer to the current version of the achievement standard as published by NZQA.
Achievement standard requirements
A table/list of names of substances, their formulae and appearance can be provided. However, these substances must not be linked as reduction-oxidation couples/pairs.
Making judgements
The following requirements should be met for both oxidation and reduction processes.
For all levels of achievement students need to identify the name or formula of oxidation-reduction species and describe the process as either oxidation or reduction with reasons (the loss/gain of electrons or change in oxidation number).
Merit also requires students to show in-depth understanding by writing balanced half equations and linking these to observations and oxidation–reduction with reasons (the number of electrons lost/gained or change in oxidation number).
Excellence also requires students to show comprehensive understanding of oxidation-reduction by linking balanced half equations, a correct overall equation, observations and electron transfer or change in oxidation number.