Which has highest oxidation state here for sulphur atom? (a) \(\mathrm{H}_{2} \mathrm{~S}\) (b) \(\mathrm{SO}_{2}\) (c) \(\mathrm{H}_{2} \mathrm{SO}_{3}\) (d) \(\mathrm{H}_{2} \mathrm{SO}_{4}\)

Understanding the oxidation number, or state, of an element within a compound is fundamental in chemistry, especially in redox reactions where electrons are transferred between atoms. The oxidation number indicates the degree of oxidation or reduction of an atom.

In practical terms, to determine the oxidation state, certain rules are used. One key rule is that the sum of all oxidation states in a molecule must be equal to the net charge of that molecule. In neutral molecules, the sum is zero. For ions, it equals the ion's charge. For example, in water (H₂O), hydrogen has an oxidation number of +1 and oxygen has -2, resulting in a net sum of 0, which is the charge of a neutral water molecule.

The process to determine the oxidation number involves a few steps such as accounting for known typical oxidation states (hydrogen is usually +1, oxygen is almost always -2), and then solving for the unknowns, making sure that the totals match the overall charge of the molecule or ion.

Sulphur can exhibit various oxidation states ranging from -2 to +6, making it a versatile element in chemical reactions. For example, in hydrogen sulfide (H₂S), sulphur has an oxidation state of -2 because the overall charge of the molecule is 0 and hydrogen generally has an oxidation state of +1.

In sulphates such as sulfuric acid (H₂SO₄), sulphur often has a high oxidation state. Here, oxygen's oxidation state is -2, and with four oxygens, that makes a total of -8. Hydrogen's +1 state times two gives us +2. To balance the molecule to 0, sulphur must have an oxidation state of +6. The ability to determine these states accurately is crucial in understanding chemical behavior and reaction mechanisms involving sulphur.

Oxidation in chemistry refers to the loss of electrons by an atom or molecule, which typically results in an increase in oxidation state. In a broader context, oxidation does not always involve oxygen. Any chemical reaction that involves the transfer of electrons between substances can be considered an oxidation event.

The oxidation state of an element in a compound provides insight into the reactive character of that substance. For instance, a high oxidation state can indicate a strong oxidizing agent, capable of accepting electrons readily. Due to this, knowing the oxidation state of the components in a compound aides in predicting and balancing chemical equations and also in inferring potential reaction pathways that a substance might undergo.