Question

Calculate Δ_{vap}H , the molar enthalpy of vaporization,
of a substance at 338.15 K,

given that its standard enthalpy of vaporization is Δ_{vap}
H^{θ} = 32.45 kJ mol^{−1} vap at 25.0ºC.

The heat capacities are C_{p,m}^{liq} = 46.20 J
K^{−1} mol^{−1} for the liquid and
C_{p,m}^{vap} = 32.20 J K^{−1}
mol^{−1} for the vapor.

Answer #1

Calculate the entropy of fusion of a compound at 25°C given
that
its enthalpy of fusion is 32 kJ mol−1 at its melting point of
146°C and
the molar heat capacities (at constant pressure) of the liquid
and solid
forms are 28 J K−1 mol−1 and 19 J K−1 mol−1,
respectively.

Calculate the entropy of fusion of a compound at 25°C given
that
its enthalpy of fusion is 32 kJ mol−1 at its melting point of
146°C and
the molar heat capacities (at constant pressure) of the liquid
and solid
forms are 28 J K−1 mol−1 and 19 J K−1 mol−1,
respectively.

A liquid has an enthalpy of vaporization of 30.8 kJ/mol. At 273
K it has a vapor pressure of 102 mmHg. What is the normal boiling
point of this liquid? (R = 8.31 J/(K· mol))

At 50.14 K a substance has a vapor pressure of 258.9 torr.
Calculate its heat of vaporization in kJ/mol it if has a vapor
pressure of 161.2 torr at 277.5 K.

1. The standard enthalpy of formation of phenol is
-165.0 kJ/mol. Calculate its standard enthalpy of combustion.
[Express your answer in units of kilojoules per mole,
kJ/mol]
C6H5OH + 7O2 --> 6 CO2 + 3H2O
ΔHc = 6ΔHf(CO2) + 3ΔHf(H2O) - ΔHf(C6H5OH) - 7ΔHf(O2)
2. Calculate the work done on a closed system consisting
of 50.0 grams of argon, assumed ideal, when it expands isothermally
and reversibly from a volume of 5.00 L to a volume of 10.00 L at...

Calculate the entropy of vaporization, ΔSvap, for A(l) at 25.0
°C given that the boiling point of A is 72.45 °C, and the molar
heat capacity of A(l) is 116.45 J/(mol·K). Assume that the molar
heat capacity of A(g) is 56.5% of that of A(l).
Calculate the standard Gibbs free energy of vaporization,
ΔG°vap, at 25.0 °C.
Determine the equilibrium constant, K, for the vaporization at
191.0 °C.
Determine the equilibrium constant, K, for the vaporization at
191.0 °C.

a. The standard enthalpy of vaporization of an inorganic
compound is 38.9 kJ/mol. If the temperature at which this phase
change occurs is 221.72 °C, determine ΔS°vap (in
J/mol/K) for this compound. Report your answer to three significant
figures.
b. The entropy of freezing of an organic compound is -21.0
J/mol/K. If ΔH°freez is -14.01 kJ/mol, determine the
temperature (in K) at which this phase change occurs. Report your
answer to two decimal places

Carbon disulfide has a molar enthalpy of vaporization of +29.2
kJmol^-1. At 268 K it has a vapor pressure of 100mmHg. Calculate
the normal temperature of carbon disulfide.

The normal boiling point of ethanol is 78.3oC. Assuming an
average molar enthalpy of vaporization value of 40.0 kJ/mol in the
temperature interval between 20.0oC and the normal boiling point,
calculate the vapor pressure of ethanol at 30.0oC.

Ethanol (C2H5OH) melts at -114 ∘C and boils at 78 ∘C. The
enthalpy of fusion of ethanol is 5.02 kJ/mol, and its enthalpy of
vaporization is 38.56 kJ/mol. The specific heat of solid and liquid
ethanol are 0.97 J/g⋅K are 2.3 J/g⋅K respectively. Q: A) How much
heat is required to convert 36.5 g of ethanol at 35 ∘C to the vapor
phase at 78 ∘C? B) How much heat is required to convert 36.5 g of
ethanol at -167...

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