Redox Flashcards
What are oxidation numbers used for?
To determine what happens to elements during oxidation and reduction reactions.
What does the oxidation number indicate?
The number of electrons used when an element is bonded to other atoms in a compound.
What is the oxidation number of uncombined elements?
0.
What is the oxidation number of any combined group 1 metal?
+1.
What is the oxidation number of any combined group 2 metal?
+2.
What is the oxidation number of fluorine when combined in a compound?
-1.
What is the typical oxidation number of hydrogen when combined in a compound?
+1.
In what exception does hydrogen have an oxidation number of -1?
In metal hydrides, e.g., NaH.
What is the typical oxidation number of oxygen when combined in a compound?
-2.
In which compound does oxygen have an oxidation number of -1?
In peroxides, e.g., hydrogen peroxide H2O2.
What happens to the oxidation number of oxygen when combined with fluorine?
Fluorine will be -1 and oxygen will be positive.
What is the general oxidation number of chlorine when combined in a compound?
-1.
What is oxidation?
Loss of electrons
Oxidation occurs when the oxidation number increases.
What is reduction?
Gain of electrons
Reduction occurs when the oxidation number decreases.
In a redox reaction, what always takes place together?
Oxidation and reduction
What happens to the species that is reduced in a redox reaction?
Gains electrons from the species that is oxidised
What is an oxidising agent?
Gains electrons (is reduced)
What is a reducing agent?
Loses electrons (is oxidised)
What should you do for each element in a redox reaction?
Write down the oxidation numbers before and after the reaction
True or False: Oxidation and reduction can occur independently in a chemical reaction.
False
Fill in the blank: The species that loses electrons in a redox reaction is called the _______.
reducing agent
Fill in the blank: The species that gains electrons in a redox reaction is called the _______.
oxidising agent
What should you state after identifying oxidation numbers in a redox reaction?
Say if the oxidation number has gone up or down
