Separation and Qualitative Analysis of Cations
Recommended for grades 9–12.
Introduction
When a chemist conducts a qualitative analysis, the primary goal is to identify the substances that are present in a mixture. It is important to separate substances from each other in a mixture, so that a confirming test can be as definitive as possible. After a thorough qualitative analysis investigation, it would be nice to say, for example, that potassium is present instead of saying merely that an alkali metal is present.
Conducting a qualitative analysis, or “qual scheme” as it is sometimes nicknamed, is a methodical process that requires great care. A qual scheme can be used to identify a wide variety of substances; in this experiment, you will focus on ions. It is fascinating to seek and identify a substance based on an established pattern of chemical behavior. You will see some very interesting things during this experiment, things that will help you understand more about the nature of cations and anions.
Consider this experiment to be more of a research project than a simple series of tests. In this experiment, you will place almost all of your emphasis on conceptual and theoretical information about the chemical behavior of ions. Other than careful measuring, there is no data to gather, graph, or examine in a qual scheme.
Objectives
In this experiment, you will
- Prepare and analyze a solution that contains ten selected cations.
- Analyze an unknown solution that contains a selection of cations.
Sensors and Equipment
This experiment requires each of the following Vernier sensors and equipment (unless otherwise noted):
pH Sensor (optional)
Additional Requirements
You may also need an interface and software for data collection. What do I need for data collection?
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer-based data collection
- List of materials and equipment
Note: The experiment preview of the computer edition does not include essential teacher information, safety tips, or sample data. Instructions for Logger Pro and other software (such as LabQuest App or TI handheld software, where available) are on the CD that accompanies the book. We strongly recommend that you purchase the book before performing experiments.
Standards Correlations
See all standards correlations for Advanced Chemistry with Vernier »
Included in the Lab Book
Vernier lab books include a CD with word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.