In the reaction: \(\mathrm{Zn}+\mathrm{NaOH} \stackrel{\Delta}{\longrightarrow} \mathrm{A}\), the product \(\mathrm{A}\) is (a) \(\mathrm{Zn}(\mathrm{OH})_{2}\) (b) \(2 \mathrm{NaZnO}_{2}\) (c) \(\mathrm{Na}_{2} \mathrm{ZnO}_{2}\) (d) None of these

Understanding chemical reactions is fundamental to chemistry as it delves into how substances interact and transform into new substances. A chemical reaction involves breaking bonds in reactants and forming new bonds in products. In the specific case of zinc (Zn) reacting with sodium hydroxide (NaOH), we observe a reaction that requires heat, indicated by the delta symbol \(\Delta\). Heat often acts as a catalyst, speeding up reactions or allowing new reaction pathways to occur.

In reactions involving metals and hydroxides, the metal can react to form a complex compound or a metal salt along with other possible byproducts like gases. For instance, zinc, a moderately reactive metal, can form a variety of compounds depending on the conditions of the reaction. With strong bases like NaOH, zinc tends to form a zincate ion. The process of determining the product involves a good grasp of reactivity series, valences, and the properties of the reactants.

Balancing chemical equations is a crucial step in the study of chemistry, ensuring that the law of conservation of mass is obeyed. This law states that matter is neither created nor destroyed in a chemical reaction. To balance an equation, one must make sure that the number of atoms for each element is the same on both sides of the equation.

Looking at the given reaction between Zn and NaOH, we initially write an unbalanced chemical equation based on the expected products. For every mole of Zn, two moles of NaOH are needed to fully react and form sodium zincate \(\mathrm{Na}_2\mathrm{ZnO}_2\) and hydrogen gas \(\mathrm{H}_2\). The balanced chemical equation, \[\mathrm{Zn} + 2\mathrm{NaOH} \stackrel{\Delta}{\longrightarrow} \mathrm{Na}_2\mathrm{ZnO}_2 + \mathrm{H}_2\], reflects the stoichiometry of the reaction, which is a vital part of understanding and predicting the outcomes of chemical reactions in both theoretical and practical applications.

Redox reactions, short for reduction-oxidation reactions, are processes where electrons are transferred between species. These reactions involve an oxidizer, which gains electrons, and a reductant, which loses electrons. The complete reaction consists of two half-reactions: one for oxidation and one for reduction.

In the case of zinc reacting with sodium hydroxide, zinc serves as the reductant as it loses electrons, and hydroxide ions (from NaOH) gain electrons, thus acting as the oxidizer. During this redox process, zinc's oxidation state increases as it forms zincate, a compound where zinc has a higher oxidation state than in its elemental form. Recognizing redox reactions is vital as they are numerous and crucial in various areas of chemistry, from electrochemistry to biochemistry, and they also provide the foundation for understanding how batteries and electrochemical cells work.