Question

The enthalpy of fusion for Lauric acid (C12H24O2) is 32.86 kJ/mol and enthalpy of vaporization is 63.82 kJ/mol. The melting point is 43.2 degrees C. How much heat is absorbed to raise the temperature of a 0.650g sample from 22.0 degrees C to 56.3 degrees C? The heat capacity of the solid is 2.15 J/g degrees C and the heat capacity of the liquid is 3.62 J/g degrees C

Answer #1

**Reaching melting point**

The heat capacity of the solid is 2.15 J/g degrees C

The soild temperature must be raised 43.2 degrees to reach melting point

(43.2-22) x 0.650 x 2.15 = **12.455** J

**Melting solid**

The enthalpy of fusion is 32.86 x 10^{3}J/mol

0.650 x 32.86 x 10^{3} = 21.359 x 10^{3}

**Heating Solid**

heat capacity of the liquid is 3.62 J/g degrees C

(56.3-43.2) x 0.650 x 3.62 = **45.35 J**

Total

The total heat required to change .65 g solid to reach 56.3:

**12.455** + **21.359 x
10**^{3} +**45.35 J = 21416 J
or 21.416 kJ**

Ethanol, C2H5OH, (MW 46.06 g/mol) melts at
-114 °C. The enthalpy of fusion is 5.02 kJ/mol. The specific heats
of solid and liquid ethanol are 0.97 J/g-K and 2.3 J/g-K,
respectively. How much heat (kJ) is needed to convert 20.0 g of
solid ethanol at -135 °C to liquid ethanol at -50 °C?
please show work

Ethanol (C2H5OH) melts at -114 °C. The enthalpy of fusion is
5.02 kJ/mol. The specific heats of solid and liquid ethanol are
0.97 J/g•K and 2.3 J/g•K, respectively. How much heat (kJ) is
needed to convert 25.0 g of solid ethanol at -125 °C to liquid
ethanol at -40 °C

Ethanol (C2H5OH) melts at -114°C. The
enthalpy of fusion is 5.02 kJ/mol. The specific heats of solid and
liquid ethanol are 0.97 J/gK and 2.3 J/gK, respectively. How much
heat (kJ) is needed to convert 25.0 g of solid ethanol at -135°C to
liquid ethanol at -50°C?

Quantity
per gram
per mole
Enthalpy of fusion
333.6 J/g
6010. J/mol
Enthalpy of vaporization
2257 J/g
40660 J/mol
Specific heat of solid
H2O (ice)
2.087 J/(g·°C) *
37.60 J/(mol·°C) *
Specific heat of liquid
H2O (water)
4.184 J/(g·°C) *
75.37 J/(mol·°C) *
Specific heat of gaseous
H2O (steam)
2.000 J/(g·°C) *
36.03 J/(mol·°C) *
At 1 atm, how much energy is required to heat 49.0 g of H2O(s)
at − 18.0 °C to H2O(g) at 135.0 °C? Heat transfer...

Ethanol (C2H5OH) melts at -114 °C. The enthalpy of fusion is
5.02 kJ/mol. The specific heats of solid and liquid ethanol are
0.97 J/g-K and 2.3 J/g-K, respectively. How much heat (kJ) is
needed to convert 25.0 g of solid ethanol at -135 °C to liquid
ethanol at -60 °C?
A. 207.3
B. -13.3
C. 6.34
D. 3617
E. 8.63

Ethanol (C2H5OH) melts at -114°C. The enthalpy of fusion is 5.02
kJ/mol. The specific heats of solid and liquid ethanol are 0.97
J/gK and 2.3 J/gK, respectively. How much heat (kJ) is needed to
convert 25.0 g of solid ethanol at -135°C to liquid ethanol at
-50°C?
A) 207.3 kJ
B) -12.7 kJ
C) 6.91 kJ
D) 4192 kJ
E) 9.21 kJ
Show all your calculations.

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.

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⋅Krespectively.
A. How much heat is required to convert 40.5
g of ethanol at 36 ∘C to the vapor phase at 78 ∘C?
B. How much heat is required to convert 40.5
g of ethanol at -161 ∘C to...

If the heat of fusion for water is 6.01 kJ/mol, the heat of
vaporization is 40.79
kJ/mol, calculate the heat transferred during the deposition of 2.0
g water vapor.
Deposition is the phase change from a vapor to a solid.

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