What type of process is the melting of ice? an exothermic reaction, because ice absorbs heat to become liquid water an endothermic reaction, because ice absorbs heat to become liquid water an exothermic reaction, because liquid water absorbs heat to become ice an endothermic reaction, because liquid water absorbs heat to become ice 5. Comparing the reactants and the products of a chemical reaction, which observation can best be used to argue that the reaction is endothermic? The volume of the reactants is greater than the volume of the products. The total energy of the reactants is equal to the total energy of the products. There are fewer chemical bonds in the reactants than there are chemical bonds in the products. The temperature of the reactants is greater than the temperature of the products.
The Correct Answer and Explanation is:
. What type of process is the melting of ice?
The melting of ice is an endothermic reaction because ice absorbs heat to become liquid water.
Explanation:
- When ice (solid water) melts, it transitions into liquid water. To do this, it requires energy to break the hydrogen bonds between the water molecules in the solid state.
- This energy is absorbed from the surroundings (often from heat), which is characteristic of an endothermic process. The process doesn’t release energy but instead takes in heat to overcome the forces that hold the solid structure together.
In contrast, an exothermic process would involve the release of energy (like the freezing of water), but in the case of melting, energy is absorbed, not released.
2. Comparing the reactants and products of a chemical reaction, which observation can best be used to argue that the reaction is endothermic?
The observation that best argues the reaction is endothermic is:
The temperature of the reactants is greater than the temperature of the products.
Explanation:
- In an endothermic reaction, energy is absorbed from the surroundings, which leads to a decrease in the temperature of the system. The products of the reaction have a higher energy state, but the system as a whole loses heat to the surroundings. This results in the temperature of the products being lower than that of the reactants.
- This is a clear sign that the reaction has absorbed energy, leading to the temperature drop.
Other observations:
- The volume of reactants vs. products doesn’t directly tell you if the reaction is endothermic.
- The total energy of reactants and products can be misleading since it’s not just about the total energy but how it’s absorbed or released (enthalpy change).
- Chemical bonds: While bond formation/rearrangement can affect energy changes, the key indicator of an endothermic reaction is the temperature drop as energy is absorbed.
Thus, temperature change is the most reliable indicator for an endothermic reaction.
