3. Given the reaction: \( \mathrm{Mg}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Mg}(\mathrm{OH})_{2}+\mathrm{H}_{2} \) At which temperature will the reaction occur at the greatest rate? \( \begin{array}{llll}25^{\circ} \mathrm{C} & \text { B) } 50^{\circ} \mathrm{C} & \mathrm{C}) ~ & 75^{\circ} \mathrm{C}\end{array} \) (D) \( 100^{\circ} \mathrm{C} \) \( \begin{array}{l}\text { Explain why: }\end{array} \)

In chemical reactions, increasing the temperature generally increases the reaction rate because the particles have more kinetic energy, leading to more frequent and forceful collisions. For the given reaction \( \mathrm{Mg}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Mg}(\mathrm{OH})_{2}+\mathrm{H}_{2} \), the ideal temperature where this would occur at the greatest rate would likely be \( 100^{\circ} \mathrm{C} \). At this temperature, not only do you ensure that the magnesium fully reacts with the water, but you also get a good balance of the gas evolution and solubility of products. However, it's important to note that at extremely high temperatures, the system may reach a point where some reactants may start to decompose or the reaction may shift to fewer products due to temperature effects on the equilibrium. Therefore, while \( 100^{\circ} \mathrm{C} \) enhances kinetic energy, one must be cautious about excessive temperatures affecting the overall reaction dynamics.