Answer:
Option 3. The catalyst does not affect the enthalpy change (
) of a reaction.
Explanation:
As its name suggests, the enthalpy change of a reaction () is the difference between the enthalpy of the products and the reactants.
On the other hand, a catalyst speeds up a reaction because it provides an alternative reaction pathway from the reactants to the products.
In effect, a catalyst reduces the activation energy of the reaction in both directions. The reactants and products of the reaction won't change. As a result, the difference in their enthalpies won't change, either. That's the same as saying that the enthalpy change of the reaction would stay the same.
Refer to an energy profile diagram. Enthalpy change of the reaction measures the difference between the two horizontal sections. Indeed, the catalyst lowered the height of the peak. However, that did not change the height of each horizontal section or the difference between them. Hence, the enthalpy change of the reaction stayed the same.
Answer:
Scientific experiments need to be repeated so that scientists can make sure the results are as accurate as possible.
Explanation:
The point of a scientific experiment is to find the answer to a question. If a scientist performs an experiment only one time, they might find an answer to their question. However, they might have messed something up, so the answer is completely wrong. Doing an experiment momre than once can help a scientist make sure that their answer is correct. I hope this helps!
(A) Gamma waves have the highest energy
