CPC CPC Physical Chemistry & Thermodynamics

Question 1

According to the first law of thermodynamics, which statement is correct?

Accepted Answer

The total energy of an isolated system is constant

Answer

Energy can be created from nothing in a chemical reaction

Answer

Entropy always increases in any process

Answer

Enthalpy equals internal energy at constant pressure

Question 2

The Gibbs free energy change (ΔG) at standard conditions for a spontaneous reaction must be:

Accepted Answer

Negative

Answer

Positive

Answer

Zero

Answer

Equal to ΔH

Question 3

The van't Hoff equation relates the equilibrium constant K to temperature through which thermodynamic quantity?

Accepted Answer

ΔH°

Answer

ΔCp

Answer

ΔS°

Answer

ΔG°

Question 4

Which colligative property is used to determine the molar mass of a large polymer in solution?

Accepted Answer

Osmotic pressure

Answer

Boiling point elevation

Answer

Freezing point depression

Answer

Vapor pressure lowering

Question 5

In the Arrhenius equation k = A·e^(−Ea/RT), increasing the temperature primarily affects the reaction rate by:

Accepted Answer

Increasing the fraction of molecules with sufficient energy to react

Answer

Decreasing the activation energy

Answer

Changing the pre-exponential factor A

Answer

Reducing molecular collisions

Question 6

Which statement correctly describes an ideal gas according to kinetic-molecular theory?

Accepted Answer

Molecules have negligible volume and no intermolecular forces

Answer

Molecules have finite volume and attractive forces between them

Answer

Pressure is independent of temperature

Answer

Molecules move in straight paths except near walls