Lab 6: Recognizing and Classifying Chemical Reactions by Types and Redox Properties

Experiment 1 – Reaction Types

You have done some work with balancing reaction equations, we can look more closely at types of reactions. In this lab you will revisit select reactions explore in lab 5. In this lab you will: 

1. to recognize and classify the four types of chemical reactions discussed in the course (combination, decomposition, single replacement, double replacement)

2. to assign oxidation numbers identify reactions as redox or non-redox 

The following learning objectives are covered in this lab.

1. Prepare for and conduct laboratory experiments to investigate scientific questions using appropriate techniques.

2. Classify reactions as combination, decomposition, single replacement or double replacement

3. Assign oxidation numbers to elements in chemical formulas

4. Classify reactions as redox or non-redox

Watch it – Hydrogen Pop Test [1:29] 
This is a video of a “pop test” is performed. A metal (Mg) is placed in a test tube with an acid (HCl). A gas forms (H2) during the reaction. In the presence of a flame, the hydrogen gas formed makes a “pop” sound. Video link: https://youtu.be/4uqlaVTKy4U 

Reaction Equation
The reaction equation for this experiment is below. Refer to this reaction equation throughout this experiment.

Mg (s) + HCl (l) ? H2 (g) + MgCl2 (s)

1)Identify the type of chemical reaction in this experiment. 

a.Combination reaction
b.Decomposition reaction
c.Single displacement reaction
d.Double displacement reaction

2)Bubbles were produced in this reaction. Look closely at the reaction equation. What do you think the chemical composition of the bubbles is? Comment in 1-2 full sentences.

Watch it – Elephant Toothpaste [stop at 1:10…but the whole video is pretty cool…] 
When something like potassium iodide (KI) is mixed with hydrogen peroxide (H2O2), oxygen gas is released (O2). If you add in some cool other ingredients like soap and food coloring, well, watch and find out what happens. Video link: https://youtu.be/Kou7ur5xt_4

Reaction Equation
The reaction equation for this experiment is below. Refer to this reaction equation throughout this experiment.

H2O2 (l) ? O2 (g) + H2O (l)

3)Identify the type of chemical reaction in this experiment. 

a.Combination reaction
b.Decomposition reaction
c.Single displacement reaction
d.Double displacement reaction

4)Bubbles were produced in this reaction. Look closely at the reaction equation. What do you think the chemical composition of the bubbles is? Comment in 1-2 full sentences.

HINT: For a “redox refresh”, you can view the mindmap available on DC Connect.

Watch it – Fe and CuSO4 [1:26] 
You can watch a demo of this experiment in the video below. [Ignore mention of “candidates” and “exam”, this is made to be a sort of test prep video…] Video link: https://youtu.be/KmhD8BmEFIo 

Reaction Equation
The reaction equation for this experiment is below. Refer to this reaction equation throughout this experiment.

Fe(s)  +  CuSO4(aq)  ?   Cu(s)  +  FeSO4(aq)

5)Identify the type of chemical reaction in this experiment. 

a.Combination reaction
b.Decomposition reaction
c.Single displacement reaction
d.Double displacement reaction