CPC CPC Physical Chemistry & Thermodynamics 2

Question 1

The Clausius-Clapeyron equation describes the relationship between vapor pressure and:

Accepted Answer

Temperature and enthalpy of vaporization

Answer

The Clausius-Clapeyron equation ln(P2/P1) = −ΔHvap/R × (1/T2 − 1/T1) relates vapor pressure changes to temperature and the molar enthalpy of vaporization.

Question 2

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number (l)

Answer

The angular momentum quantum number l defines the orbital shape: l=0 (s, spherical), l=1 (p, dumbbell), l=2 (d, more complex).

Question 3

For a reaction at equilibrium, doubling the concentration of a reactant that appears as first order will change the reaction quotient Q by a factor of:

Accepted Answer

2

Answer

If a reactant appears as first order in the rate expression, doubling its concentration multiplies Q by 2, shifting the reaction toward products if Q > K.

Question 4

The Born-Haber cycle is used to calculate the lattice energy of an ionic compound by applying:

Accepted Answer

Hess's law to a series of enthalpy steps

Answer

The Born-Haber cycle applies Hess's law, summing experimentally known enthalpies (sublimation, ionization, electron affinity, dissociation, formation) to determine the otherwise inaccessible lattice energy.

Question 5

Which spectroscopic technique measures the absorption of microwave radiation to give information about molecular bond lengths and angles?

Accepted Answer

Rotational (microwave) spectroscopy

Answer

Microwave (rotational) spectroscopy probes transitions between rotational energy levels, providing precise molecular geometry data including bond lengths and bond angles.

(CPC) Certified Professional Chemist Practice Test

(CPC) Certified Professional Chemist Practice Test

CPC CPC Physical Chemistry & Thermodynamics 2