Answer:
The water is completely vaporized at this stage.
Step-by-step explanation:
The complete question is
If 5.0 kJ of energy is added to a 15.5-g sample of water at 10.°C, the water is
-boiling
-completely vaporized
-frozen solid
-decomposed
-still a liquid
Energy added = 50 kJ = 50000 J
mass of water = 15.5 g = 0.0155 kg
temperature of water = 10 °C
We know that the energy posses by a mass of water at a given temperature is given as
H = mcT
where H is the energy possessed by the mass of water
m is the mass of the water
c is the specific heat capacity of water = 4200 J/ kg- °C
T is the temperature of the water
substituting values, the energy of this amount of water is
H = 0.0155 x 4200 x 10 = 651 J
If 50 kJ is added to the water, the energy increases to
50000 J + 651 J = 50651 J
Temperature of this water at this stage will be gotten from
H = mcT
we solve for the new temperature
50651 = 0.0155 x 4200 x T
50651 = 65.1 x T
T = 50651/65.1 = 778.05 °C
This temperature is well over 100 °C, which is the vaporization temperature of water, but less than 3000 °C for its molecules to decompose.