Chapter 3 - Redox reactions (L) Flashcards
What does oxidation mean in terms of electrons?
Loss of electrons
What does reduction mean in terms of electrons?
Gain of electrons
What does oxidation mean in terms of hydrogen?
Loss of hydrogen
What does reduction mean in terms of hydrogen?
Gain of hydrogen
In a redox reaction, what does it mean to be the reducing agent?
The species that loses electrons
In a redox reaction, what does it mean to be the oxidising agent?
The species that gains electrons
What is the sum of the oxidation numbers of all the elements in a neutral compound?
Zero
What is the sum of the oxidation numbers of all elements in an ion?
The sum will be equal the charge on the ion
The most electronegative element in a substance is always given what type of oxidation number?
The most electronegative element is always given a negative oxidation number
What is the oxidation number of fluorine always?
-1
What is the oxidation number of hydrogen?
It is +1 when combined with more electronegative elements, and -1 when combined with less electronegative elements
What is the oxidation number of oxygen?
It is -2, except in peroxides where it is -1, or when combined with fluorine where it is +2
What happens to an element’s oxidation number when it is oxidised?
The oxidation number increases
What happens to an element’s oxidation number when it is reduced?
The oxidation number decreases
What do you need to make sure is the same when writing full equations from ionic half-equations?
The number of electrons in either half equation is the same. This can be done by multiplying t either one of both of the whole equations to reach a common denominator of electrons.
E.g. if one half equation had 2 electrons, and the other 5, you would multiply the whole of the first by 5, and the whole of the second by 2, to reach 10 electrons on both sides
