Identify the species oxidized and the species reduced in each of these redox equations
A. 3Br2 + 2Ga -> 2GaBr3
B. HCL + Zn -> ZnCl2 + H2
C. Mg + N2 -> Mg3N2
A. 3Br2 + 2Ga -> 2GaBr3
In this equation, Br2 is being reduced and Ga is being oxidized.
B. HCL + Zn -> ZnCl2 + H2
In this equation, HCl is being reduced and Zn is being oxidized.
C. Mg + N2 -> Mg3N2
In this equation, N2 is being reduced and Mg is being oxidized.
To identify the species oxidized and the species reduced in each redox equation, we need to assign oxidation numbers to the elements in the reactants and products.
A. 3Br2 + 2Ga -> 2GaBr3
In this equation, bromine (Br) is changing from an oxidation state of 0 on the left side of the equation to an oxidation state of -1 in GaBr3 on the right side. Therefore, bromine is being reduced.
Gallium (Ga) is changing from an oxidation state of 0 on the left side of the equation to +3 in GaBr3 on the right side. Therefore, gallium is being oxidized.
Species oxidized: Ga
Species reduced: Br
B. HCl + Zn -> ZnCl2 + H2
In this equation, hydrogen (H) is changing from an oxidation state of +1 in HCl on the left side of the equation to 0 in H2 on the right side. Therefore, hydrogen is being reduced.
Zinc (Zn) is changing from an oxidation state of 0 on the left side of the equation to +2 in ZnCl2 on the right side. Therefore, zinc is being oxidized.
Species oxidized: Zn
Species reduced: H
C. Mg + N2 -> Mg3N2
In this equation, magnesium (Mg) is changing from an oxidation state of 0 on the left side of the equation to +2 in Mg3N2 on the right side. Therefore, magnesium is being oxidized.
Nitrogen (N) is changing from an oxidation state of 0 on the left side of the equation to -3 in Mg3N2 on the right side. Therefore, nitrogen is being reduced.
Species oxidized: Mg
Species reduced: N
Okay so you have to first balance them and then count how much you added or minus in each equation.
Two definitions, only one of which must be memorized. The other you will know is the opposite of what you memorized.
Oxidation is the loss of electrons.
Reduction is the gain of electrons.
I will help you out on the first one.
Br goes from zero on the left to -1 on th right.
Ga goes from zero on the left to +3 on the right.
Here is a site that will help you identify the oxidation state of an element.
http://www.chemteam.info/Redox/Redox-Rules.html