Question

An ideal gas is compressed in a closed container, its U?
A. Increases
B. Decreases
C. Remains same
D. Both (1) and (2)

Answer 1

Hint- In order to deal with this question first we will talk about the term compression then we will see what factors we get affected when an ideal gas is compressed in a closed container, according to these factors we will comment about its internal energy.

Complete step-by-step answer:
Compression: As we pinch something to make it lighter, the compression occurs. The atoms in a gas have plenty of space between them, and can quickly travel around.
An ideal gas is a theoretical gas consisting of several uniformly traveling point particles which are not subject to collision between particles. The ideal definition of gas is useful as it obeys the ideal gas law, a simple state equation which can be studied under statistical mechanics.
At most common conditions (e.g. at normal temperature and pressure), most actual gasses are qualitatively as an ideal gas. Under acceptable tolerances, certain gases such as nitrogen, oxygen, hydrogen, noble gases and some heavy gasses such as carbon dioxide can be viewed as ideal gases. Generally speaking, a gas behaves more like an ideal gas at higher temperature and lower pressure, since the potential energy due to intermolecular forces becomes less significant compared to the kinetic energy of the particles, and the size of the molecules becomes less significant compared to the empty space between them.
When an ideal gas is compressed in a closed container it raises the internal energy U. Compressing an ideal gas increases its temperature and its internal energy increases since $U = f\left( t \right)$ for an ideal gas.
Hence, when an ideal gas is compressed in a closed container its U increases.
So, the correct answer is option A.

Note- Internal energy is characterized as the energy linked to the spontaneous, disordered molecular motion. It is distinguished in size from the macroscopic ordered energy associated with moveable objects; it corresponds to the atomic and molecular dimension of the intangible microscopic force. A system's intrinsic energy is associated with the spontaneous, disordered molecular motion; the overall (intrinsic) energy in a system includes potential, and kinetic energy. This is the sum of all the microscopic energies such as: kinetic translational energy, vibrational and rotational kinetic energy.