If the value of ΔH is positive for a reaction, it means that the reaction is?
Answer Details
If the value of \(\Delta H\) is positive for a reaction, it means that the reaction is endothermic.
\(\Delta H\) stands for the change in enthalpy, which is a measure of the amount of heat absorbed or released during a chemical reaction. A positive value of \(\Delta H\) indicates that the reaction absorbs heat from the surroundings. This means that the reaction requires an input of energy in order to proceed.
Endothermic reactions are those that absorb heat from the surroundings. In an endothermic reaction, the products have a higher energy than the reactants. The energy is absorbed from the surroundings, so the surroundings become cooler. For example, melting ice is an endothermic process because it absorbs heat from the surroundings.
On the other hand, exothermic reactions release heat to the surroundings, and have a negative \(\Delta H\) value. These reactions are often spontaneous and occur without the need for an external energy input. For example, burning wood is an exothermic process because it releases heat to the surroundings.
Therefore, if the value of \(\Delta H\) is positive for a reaction, it means that the reaction is endothermic.