Is the following a redox reaction? Justify your answer.
CaCO3 CO2 +CaO
Yes, the given reaction is a redox reaction. This can be justified by identifying the changes in oxidation numbers of the elements involved in the reaction.
In CaCO3, the oxidation state of Ca is +2, the oxidation state of C in CO3 is +4, and the oxidation state of each O is -2. In CO2, the oxidation state of C is +4, and the oxidation state of each O is -2. In CaO, the oxidation state of Ca is +2, and the oxidation state of each O is -2.
So, in the reaction: CaCO3 -> CO2 + CaO, the oxidation state of Ca changes from +2 to +2, but the oxidation state of C changes from +4 to +4 and the oxidation state of O changes from -2 to -2. Since there is a change in oxidation state for C, it can be concluded that this is a redox reaction.
To determine whether the given equation represents a redox reaction, we need to check if there is a change in the oxidation numbers of any elements involved in the reaction.
In the given equation:
CaCO3 → CO2 + CaO
We can assign oxidation numbers to the elements as follows:
- Let's assume that the oxidation number of carbon (C) is x.
- The oxidation number of oxygen (O) is typically -2.
- The oxidation number of calcium (Ca) is typically +2.
In CaCO3 (calcium carbonate), the sum of the oxidation numbers should be zero:
(+2) + x + 3(-2) = 0
2 + x - 6 = 0
x - 4 = 0
x = +4
So, the oxidation number of carbon (C) in CaCO3 is +4.
In CO2 (carbon dioxide), the sum of the oxidation numbers is also zero:
x + 2(-2) = 0
x - 4 = 0
x = +4
So, the oxidation number of carbon (C) in CO2 is +4.
In CaO (calcium oxide), the sum of the oxidation numbers is also zero:
(+2) + x = 0
2 + x = 0
x = -2
So, the oxidation number of oxygen (O) in CaO is -2.
By comparing the oxidation numbers of carbon and oxygen, we can conclude that the oxidation states of carbon and oxygen have not changed in this reaction. Therefore, the given equation, CaCO3 → CO2 + CaO, does not represent a redox reaction.