How much heat is released upon converting one mole of steam (18.0 g) from 100.0 ∘C to water at 25.0 ∘C? please show work and constants, trying to figure out how it works. only given the heat capacity for steam and water so try to only use that

Respuesta :

Answer : The amount of heat released, -35057 J

Solution :

Process involved in the calculation of heat released :

[tex](1):H_2O(g)(100^oC)\rightarrow H_2O(l)(100^oC)\\\\(2):H_2O(l)(100^oC)\rightarrow H_2O(l)(25^oC)[/tex]

Now we have to calculate the amount of heat released.

[tex]Q=\Delta H_{condensation}+[m\times c_{p,l}\times (T_{final}-T_{initial})][/tex]

where,

Q = amount of heat released = ?

m = mass of water = 18 g

[tex]c_{p,l}[/tex] = specific heat of liquid water = [tex]4.18J/g^oC[/tex]

[tex]\Delta H_{condensation}[/tex] = enthalpy change for condensation = -40700 J/mole

Now put all the given values in the above expression, we get

[tex]Q=-40700J+[18g\times 4.18J/g^oC\times (100-25)^oC][/tex]

[tex]Q=-35057J[/tex]

Therefore, the amount of heat released, -35057 J

Answer: 46418.4 Joules

Explanation:

The conversions involved in this process are :

[tex]H_2O(g)(100^0C)\rightarrow H_2O(l)(100^0C)[/tex]

[tex]H_2O(l)(100^0C)\rightarrow H_2O(l)(25^0C)[/tex]

Now we have to calculate the enthalpy change.

[tex]Q=[[m\times \Delta H_{condensation}]+[m\times c_{p,l}\times (T_{final}-T_{initial})][/tex]

where,

Q = amount of heat released = ?

m = mass of water = 18 g

[tex]c_{p,l}[/tex] = specific heat of liquid water = [tex]4.18J/g^oC[/tex]

[tex]\Delta H[/tex] = enthalpy change = ?

m = mass of water = 25 g

[tex]\Delta H_{condensation}[/tex] = enthalpy change for condensation = 2265 J/g

Now put all the given values in the above expression, we get

[tex]Q=[(18g\times 2265J/g)+(18g\times 4.18J/g^oC\times (100-25))^oC][/tex]

[tex]Q=40770+5648.4=46418.4J[/tex]

Therefore, the amount of heat released is 46418.4 J.