Complete and balance the following oxidation-reduction reactions, which give the highest possible oxidation state for the oxidized atoms. (a) \(\mathrm{Al}(s)+\mathrm{F}_{2}(g) \rightarrow\) (b) \(\mathrm{Al}(s)+\operatorname{CuBr}_{2}(a q) \rightarrow\) (single displacement) (c) \(\mathrm{P}_{4}(s)+\mathrm{O}_{2}(g) \rightarrow\) (d) \(\mathrm{Ca}(s)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (products are a strong base and a diatomic gas)

Redox reactions, short for reduction-oxidation reactions, are chemical processes where the oxidation state of atoms changes through the transfer of electrons. In such reactions, one element gains electrons (reduction) while another loses electrons (oxidation). A classic example is the reaction of aluminum with fluorine, where aluminum gets oxidized, gaining a +3 oxidation state, and fluorine is reduced, with each fluorine atom achieving a -1 state.

Understanding redox reactions is key to mastering chemistry because they play an essential role in processes like energy production, metabolism, and the functioning of batteries. Balancing redox reactions requires an equal number of electrons to be lost and gained, ensuring charge conservation throughout the reaction.

Oxidation states, also known as oxidation numbers, provide insight into the distribution of electrons among atoms in a molecule. They are hypothetical charges that an atom would have if all bonds it participated were ionic. For pure elements, the oxidation state is zero. During a chemical reaction, the change in oxidation state indicates how many electrons are transferred.

For example, in the oxidation of aluminum from the elemental state to aluminum fluoride, the oxidation state of aluminum changes from 0 to +3. The assignment of correct oxidation states is crucial for balancing redox reactions because it allows for the conservation of charge and matter.

Balancing chemical reactions is a fundamental skill in chemistry that ensures the law of conservation of mass is upheld. This means that the number of atoms for each element must be the same on both sides of the equation. For redox reactions, the additional step of balancing the exchange of electrons is also necessary.

To properly balance a reaction, like the reaction of calcium with water, you must determine the correct coefficients that lead to an equal number of atoms for each element on both sides and ensure that the electrons lost equal the electrons gained. This will commonly involve a bit of trial and error before you find the right combination.

Single displacement reactions are a type of redox reaction where an element in a compound is replaced by another element. These reactions typically occur when a more reactive metal displaces a less reactive metal from its compounds. For instance, aluminum is more reactive than copper, so in the reaction with copper(II) bromide, aluminum displaces copper, forming aluminum bromide and elemental copper.

Understanding the reactivity series of metals is crucial for predicting and balancing single displacement reactions. It guides which metal will displace another and aids in quickly deducing the outcomes and balancing the overall reaction, as seen when aluminum replaces copper in copper(II) bromide to produce aluminum bromide and metallic copper.