What volume and mass of steam at 100 Celsius and 760. torr (or 1 atm) would release the same amount of energy as heat during condensation as 65.5cm^3 of liquid water would release during freezing?

Respuesta :

  
As we know that
1 cu cm H2O = 1 mL H2O = 1g H2O 
now

Heat of fusion of water = 79.8 cal/g 
and

Heat of vaporization of water = 540 cal/g 

Atomic weight of water : H=1 O=16 H2O=18 
now by calculating and putting values

65.5gH2O x 79.8cal/gH2O x 1gH2O/540cal = 9.68g H2O (steam) 

9.68gH2O x 1molH2O/18gH2O x 22.4LH2O/1molH2O = 12.0 L H2O
hope it helps

Explanation:

The given data is as follows.

          Volume = 65.5 [tex]cm^{3}[/tex]

          Temperature = [tex]100^{o}C[/tex]

          Pressure = 760 torr or 1 atm

As we know that q = [tex]mL_{f}[/tex]  

where,    m = mass

            [tex]L_{f}[/tex] = latent heat of fusion

As density of water is 1.0 g/ml. Hence, mass of water in liquid state is calculated as follows.

                   mass = density × volume

                            = [tex]1.00 g/ml \times 65.5 ml[/tex]            (as 1 ml = 1 [tex]cm^{3}[/tex])

                           = 65.5 g

As heat of fusion of ice is 333.55 J/g. Hence, calculate the heat energy as follows.

                    q = [tex]mL_{f}[/tex]  

                       = [tex]65.5 g \times 333.55 J/g[/tex]

                       = 21847.52 J

And, heat of vaporization of water is 2257 J/g.

Also,                q = [tex]mL_{v}[/tex]

where,      [tex]L_{v}[/tex] = heat of vaporization

Therefore, we will calculate the mass of steam as follows.

                        q = [tex]mL_{v}[/tex]

                     21847.52 J = [tex]m \times 2257 J/g[/tex]            

                       m = 9.68 g

It is known that density of steam water is 0.0006 g/ml. Hence, calculate the volume of steam as follows.

                Volume = [tex]\frac{mass}{Density}[/tex]

                              = [tex]\frac{9.68 g}{0.0006 g/ml}[/tex]

                              = 16133.33 ml

or,                           = 16.13 L             (as 1 L = 1000 ml)

Thus, we can conclude that 9.68 g of steam condenses will release the same amount of energy as 65.5 g of freezing liquid water and its volume is 16.13 L.

Q&A Education