Laboratory 7 Procedure : The Chemistry of Metals: Exploring Reactivity
Background:
Let’s consider single displacement reaction, where one element displaces another in a compound. This reaction can be summarized by the following general equation:
A(s) + BC(aq) => B(s) + AC(aq)
Figure 1: A is a free metal (s), BC is an ionic compound dissolved in water (aq), B is a free mental (s), and AC an ionic compound dissolved in water (aq).
In this type of reaction, there is a competition between the two elements (A and B). During this single displacement, redox reaction one element loses electron (or electrons) to the other element.
We can simplify the reaction by writing net ionic equation, that will show only the electron exchange between elements:
A(s) + B+ (aq) => A+(aq) + B(s)
Figure 2: A(s) is a free metal that is donating an electron and dissolving into the solution-forming cation A+(aq), a cation B+ (aq) is accepting an electron and converting to the free metal B(s).
Above reaction occurs when free metal A(s) is more reactive then ion B+ (aq) in the solution.
However, in cases where free metal A(s) is less reactive then ion B+ (aq) the reaction does not occur.
There are four signs to look for, when analyzing a chemical reaction:
1. Dramatic color change
2. Gas evolution (formation of bubbles)
3. Precipitate formation (formation of the solid)
4. Temperature change
In this lab you will determine order the relative reactivity of four metals: copper, magnesium zinc and led by performing series of redox reactions.
The main objective of this lab is to enhance your understanding of relative reactivity of metals.
Before you start this laboratory assignment, you are encouraged to research relative reactivity series and read pages 651-653 in your Textbook. Throughout this laboratory assignment, you will be required to analyze a chemical reaction in terms of single displacement redox reaction. Be sure to record all observations and any relevant notes that you think you will need to include in your laboratory report.
Take a moment to formulate and write down a hypothesis answering the question what group of metals is more reactive alkaline earth metals or transitional metals?
Pre-Lab questions:
1. Using your own words, explain what is a relative reactivity?
2. What is a redox reaction?
3. What happens to the electrons during a redox process?
Procedure:
Preparing the Lab 5
From the course home page, click on the Virtual Lab Tutorial link to watch the overview of using the virtual lab.
1. From the course home page, access the lab environment by clicking on the Virtual Lab
link.
2. After the lab environment loads, click ‘File’ then ‘Load an Assignment.’
3. Select the ‘Redox’ category,
4. Select the ‘Redox Reaction Series’ assignment.
5. At this point, you have prepared the laboratory for the first experiment with the require supplies to complete your experiments.
6. If you haven’t already done so, formulate a hypothesis what group of metals is more reactive alkaline earth metals or transitional metals? as you will need to include this in your final report.
