Chemistry Test Physical Chemistry 3

Question 1

Which of the following best describes the Maxwell-Boltzmann distribution for an ideal gas at higher temperature?

Accepted Answer

Broader and shorter peak shifted to higher speeds

Answer

Higher temperature increases average molecular speed and broadens the distribution, resulting in a lower, wider curve shifted toward higher speeds.

Question 2

The critical point of a substance is defined as the temperature and pressure above which:

Accepted Answer

Liquid and gas phases become indistinguishable

Answer

Above the critical point, distinct liquid and gas phases cease to exist, and the substance exists as a supercritical fluid.

Question 3

Henry's Law states that the solubility of a gas in a liquid is:

Accepted Answer

Directly proportional to partial pressure of the gas

Answer

Henry's Law: C = kH·P, where gas solubility (C) is directly proportional to the partial pressure (P) of the gas above the solution.

Question 4

In electrochemistry, the standard cell potential E°cell is related to the standard Gibbs free energy by:

Accepted Answer

ΔG° = −nFE°cell

Answer

The relationship is ΔG° = −nFE°cell, where n is moles of electrons transferred and F is Faraday's constant.

Question 5

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number (l)

Answer

The angular momentum (azimuthal) quantum number l determines orbital shape: l=0 is s (spherical), l=1 is p (dumbbell), l=2 is d, etc.

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