A substance whose 0xidation number decreases during a chemical reaction
To determine a substance whose oxidation number decreases during a chemical reaction, we first need to understand what an oxidation number represents. The oxidation number is a hypothetical charge that an atom would have if all the bonds in a compound were purely ionic. It is used to track the movement of electrons during a reaction.
During a chemical reaction, an atom's oxidation number can either increase (oxidation) or decrease (reduction). A substance that experiences a decrease in oxidation number is considered to be reduced. This occurs when an atom gains electrons or experiences a decrease in its oxidation state.
To identify a substance whose oxidation number decreases during a chemical reaction, you can follow these steps:
1. Determine the oxidation number of the atoms in the reactants and products before and after the reaction.
2. Compare the oxidation numbers of the same atom between the reactants and products.
3. If the oxidation number of an atom decreases from reactants to products, then that atom has undergone reduction.
Keep in mind that the reaction equations and the specific elements involved will determine which substance undergoes reduction. In general, elements with higher oxidation numbers in the reactants are more likely to be reduced.
It's also important to note that oxidation and reduction always occur simultaneously in a reaction, as electrons are transferred from one species to another. The substance that undergoes reduction is often paired with another substance that undergoes oxidation to maintain charge balance. This is known as a redox (reduction-oxidation) reaction.