Chemical Reactions to Identify Various Cations and Anions

TASK DETAILS

Context

Scientists have established significant understandings of chemical reactions. They have done this using observations and fair testing to test hypotheses and establish the scientific body of knowledge. Science is how we establish knowledge using fair testing and observations. You have investigated some chemical reactions experimentally during this unit. You will have collected and presented data, discussed results and you have discussed and justified conclusions as preparation for this assessment task.

Purpose

 To inform the audience about your investigation.

 To demonstrate your knowledge and understanding of your investigation

 To demonstrate your knowledge and understanding of a formal scientific report.

Audience

 Student and teacher

TASK DESCRIPTION

You are to conduct a number of chemical reactions to identify various cations and anions. You will then be asked to identify an unknown salt. Separating and detecting cations and anions in a substance is termed qualitative analysis. By discovering the qualities of these ions you will be able to identify the sample substance.

You will be asked to complete a practical report of your findings on this experiment by following the method and flow chart on the next page. You will discuss your results and formulate a conclusion from your data.

Identification of an Unknown Substance

This experiment will be completed in class and a formal report will be submitted using the following headings:

Title: (with date of experiment and partner's name)

Aim: To perform tests on anions and cations and use the results to identify an unknown ionic compound (salt).

Introduction: (with in-text referencing) (Please refer to handout for how to prepare an experimental report)

Include

* definition of ionic compounds.

* definition of cations and anions.

* description of qualitative chemical analysis.

* explanation why different cations produce different flame colours.

* An explanation for why some cation/anion combinations form precipitates and others don't.

http://www.chemtopics.com/aplab/analmix.pdf

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