Which statement is true about solid reactions?

In solid reactions, it is indeed often the case that high temperatures and pressures are involved. This is because many solid-state reactions are characterized by the need to overcome significant activation energy barriers. Applying heat can provide the energy necessary to facilitate the reaction, allowing the reactants to break their bonds and transform into products. Additionally, when reacting solids (such as in solid-state synthesis or metallurgical processes), the increased temperature can enhance the mobility of atoms and ions within the solids, promoting diffusion and enhancing reaction rates.

Under certain circumstances, particularly in the context of materials science and solid-state chemistry, high pressure can also play a crucial role in driving reactions that might not occur at ambient conditions. Therefore, the statement that solid reactions often involve high temperatures and pressure accurately reflects the typical conditions required for these reactions to occur effectively.