How much energy must be removed from a 94.4 g sample of benzene (molar mass= 78.11 g/mol) at 322.0 K to solidify the sample and lower the temperature to 205.0 K? The following physical data may be useful.
ΔHvap = 33.9 kJ/mol
ΔHfus = 9.8 kJ/mol
Cliq = 1.73 J/g°C
Cgas = 1.06 J/g°C
Csol = 1.51 J/g°C
Tmelting = 279.0 K
Tboiling = 353.0 K
At 322 K, benzene is still a liquid, but it freezes at 279 K.
Therefore, the only phase-transition that we are interested in
is:
C6H6(l) ---> C6H6(s)
There are two types of energy that need to be considered.
a) The specific heat of liquid that occurs while the temperature is
above the freezing point.
b) Hfus at the freezing point until all of the benzene turns into
solid.
c) The specific heat of the solid until you reach your desired
temperature
The very first thing you need to do before you start mingling with
the energies is to calculate the number of moles of benzene that
you have:
moles = (94.4 g C6H6) x [(1 mole C6H6)/(78.11 g C6H6)] = 1.21 moles
C6H6
Alright, now let's calculate the amount of energy lost at the three
regimes:
a) (94.4 g) x (1.73 J/g*K) x (279 K - 322 K) = - 7.02 kJ
b) - (9.8 kJ/mol) x (1.21 moles C6H6) = - 11.9 kJ
c) (94.4 g) x (1.51 J/g*K) x (205 K - 279 K) = - 10.5 kJ
Thus, the total energy lost to lower 94.4 g of benzene to 205 K is
- 29.4 kJ
How much energy must be removed from a 94.4 g sample of benzene (molar mass= 78.11...
Question 3 7.5 pts How much energy must be removed from a 22.2 g sample of benzene CH) at 85.0°C to solidify the sample and lower the temperature to -7.5°C? The following physical data may be useful. AHvap = 33.9 kJ/mol AHfus = 9.8 kJ/mol Cliquid - 1.73J/gºC Cgas = 1.06 J/g°C Csolid - 1.51 J/g°C Tmelting = 6,0 °C Tboiling = 80.0°C 29.4 kJ 15.8 kJ O 17.6 kJ O 70.2 kJ 10.5 kJ
How much energy must be removed from a 125 g sample of benzene (molar mass= 78.11 g/mol) at 425.0 K to liquify the sample and lower the temperature to 335.0 K? The following physical data may be useful. ?Hvap = 33.9 kJ/mol ?Hfus = 9.8 kJ/mol Cliq = 1.73 J/g
You have a 10.0 g sample of water at 373 K. How much energy must you use to turn this into steam? AHvap = 40.7 kJ/mol AHfus = 6.02 kJ/mol Cliq - 4.184 J/g °C Cgas = 2.01 J/gºC Csol - 2.09 J/g°C Tmelting = 273.0 K Tboiling = 373.0 K 45346 3472.72 J 22598.63 -4534.6
How much energy is required to heat 36.0 g H2O from a liquid at 65°C to a gas at 115°C? The following physical data may be useful. ΔHvap = 40.7 kJ/mol Cliq = 4.18 J/g°/sup>C Cgas = 2.01 J/g°/sup>C Csol = 2.09 J/g°/sup>C Tmelting = 0°/sup>C Tboiling = 100°/sup>C
How much energy is required to heat 87.1 g acetone (molar mass=58.08 g/mol) from a solid at -154.0°C to a liquid at -42.0°C? The following physical data may be useful. ΔHfus = 7.27 kJ/mol Cliq = 2.16 J/g°C Cgas = 1.29 J/g°C Csol = 1.65 J/g°C Tmelting = -95.0°C
Only do question 4-6 show all work CHM 107, Quiz 1 Name How much energy must be removed from a 125 g sample of benzene (CH6 vapor at 425.0 K to make it a solid at 200.0 K? Use the following steps to get to your answer. You MUST show your work to receive any credit. The following physical data for benzene may be useful. See announcement for due date. AHvap 33.9 kJ/mol Cliq 1.73 J/g C Cgas 1.06 Csol...