Assigning Oxidation States: Rules & Lewis Structures

[Omid]

The book I'm reading, has suggested to methods for assigninig the oxidation statetes in a compound. The first method includes drawing the Lwis structure of the compound. And the second one is based on some rules.
As I'm a beginner in chemsitry there are so many compounds which I can't draw it's Lwis structure. So the first method doesn't work always (for me as a biginner). And in the list of the rules there is no rule for so many situations. For example for these compounds I don't know what to do:
AlCl(3),
ICl,
MgSO(4)
I want to know what will happen. Will I find some more rules as I advance in chemistry?

 

[member 553083]

Is there any other method for assigning oxidation numbers?Yes, as you advance in chemistry, you will learn more rules to assign oxidation numbers. In addition to the two methods you mentioned, there are a few other methods that can be used to assign oxidation numbers. These include the use of half-reaction equations and the knowledge of common elements and their oxidation states. You can also use a periodic table to help determine oxidation states. Furthermore, certain elements have characteristic oxidation states that can be used as a guideline. For example, oxygen is usually -2, hydrogen is +1, and chlorine is -1. Using this information and the other methods mentioned, you should be able to assign oxidation numbers to most compounds.

 

[thepatientmental]

It is common for beginners in chemistry to struggle with assigning oxidation states, as it requires a solid understanding of molecular structures and chemical bonding. Drawing Lewis structures can be a helpful tool, but as you mentioned, it may not always be feasible for every compound.

Fortunately, there are some general rules that can be applied to assign oxidation states. These rules are based on the electronegativity of the elements involved in the compound, as well as their oxidation states in known compounds.

For example, in compounds like AlCl3 and ICl, the electronegativity difference between Al and Cl, and I and Cl, respectively, can help determine the oxidation state of each element. In general, the more electronegative element will have a negative oxidation state, while the less electronegative element will have a positive oxidation state.

In the case of MgSO4, the oxidation state of Mg can be determined by considering the overall charge of the compound (which is 0) and the known oxidation states of the other elements (S in this case has an oxidation state of +6). This means that Mg must have an oxidation state of +2 to balance out the overall charge.

As you continue to study chemistry, you will learn more about the properties of elements and how they affect their oxidation states. This will help you develop a better understanding of how to assign oxidation states in more complex compounds. Additionally, practicing with different compounds and seeking help from your teacher or classmates can also improve your skills in this area.

Remember, assigning oxidation states is not an exact science and there may be exceptions to the rules. However, with practice and a solid understanding of chemical bonding, you will become more confident in assigning oxidation states.