The First Law of Thermodynamics tells us
A) that the energy of the universe is always increasing.
B) that the energy of the universe is a constant.
C) that the energy for a chemical reaction is a constant.
D) that a chemical reaction will always release energy.
The Correct Answer and Explanation is :
The correct answer is:
B) that the energy of the universe is a constant.
Explanation:
The First Law of Thermodynamics, also known as the Law of Energy Conservation, states that energy cannot be created or destroyed, only transferred or converted from one form to another. This principle is foundational to both physics and chemistry, dictating how energy behaves in all natural processes.
In mathematical terms, the First Law is often expressed as:
[
\Delta U = Q – W
]
where:
- ( \Delta U ) is the change in internal energy of a system,
- ( Q ) is the heat added to the system,
- ( W ) is the work done by the system.
This equation tells us that any energy added to a system as heat must either increase its internal energy or be used to do work.
Since energy cannot be created or destroyed, the total energy in the universe remains constant—it simply changes forms. For example, in chemical reactions, energy may be stored in chemical bonds and later released as heat or work, but the overall energy remains the same.
Now, let’s examine the incorrect answer choices:
- A) “The energy of the universe is always increasing” – Incorrect, because while entropy (disorder) increases over time (Second Law of Thermodynamics), total energy remains constant.
- C) “The energy for a chemical reaction is a constant” – Incorrect, because energy can be exchanged between a system and its surroundings.
- D) “A chemical reaction will always release energy” – Incorrect, because some reactions absorb energy (endothermic reactions).
Thus, the correct answer remains B: The energy of the universe is a constant.
Now, I’ll generate an image related to the First Law of Thermodynamics.
Here is an image illustrating the First Law of Thermodynamics, depicting the energy cycle with heat ((Q)), work ((W)), and internal energy ((U)) in a closed system. Let me know if you need any modifications or additional details!