CALCULATE THE ENERGY PRESSURE WHEN 20 GRAMS OF STEAM AT 100 DEGREES CELSIUS COOLS TO ICE AT-20 DEGREES CELSIUS.

To calculate the energy pressure when 20 grams of steam at 100 degrees Celsius cools to ice at -20 degrees Celsius, we need to consider the energy changes during the phase transitions and temperature changes.

First, we need to calculate the energy required to cool the steam from 100 degrees Celsius to 0 degrees Celsius. The specific heat capacity of water is 4.18 J/g°C.

Energy required = mass * specific heat capacity * temperature change
= 20 g * 4.18 J/g°C * (0°C - 100°C)
= -8360 J

Next, we need to calculate the energy required for the phase change from water at 0 degrees Celsius to ice at 0 degrees Celsius. The heat of fusion for water is 333.55 J/g.

Energy required = mass * heat of fusion
= 20 g * 333.55 J/g
= 6671 J

Lastly, we need to calculate the energy required to cool the ice from 0 degrees Celsius to -20 degrees Celsius. The specific heat capacity of ice is 2.09 J/g°C.

Energy required = mass * specific heat capacity * temperature change
= 20 g * 2.09 J/g°C * (0°C - (-20°C))
= 832 J

Now we can calculate the total energy required:

Total energy required = Energy required to cool from 100°C to 0°C + Energy required for phase change + Energy required to cool from 0°C to -20°C
= -8360 J + 6671 J + 832 J
= -860 J

Since we are dealing with energy, the pressure remains unchanged throughout these processes. Therefore, the energy pressure when 20 grams of steam at 100 degrees Celsius cools to ice at -20 degrees Celsius is -860 J.

To calculate the energy pressure when steam at 100 degrees Celsius cools to ice at -20 degrees Celsius, we can use the formula for specific latent heat:

Q = m * L

where:
Q is the energy change,
m is the mass of the substance, and
L is the specific latent heat.

First, we need to determine the energy required to cool the steam from 100 degrees Celsius to 0 degrees Celsius. We can use the formula:

Q1 = m1 * c1 * ΔT1

where:
Q1 is the energy required to change the temperature of the steam,
m1 is the mass of the steam,
c1 is the specific heat capacity of water (4.18 J/g°C), and
ΔT1 is the change in temperature (100°C - 0°C).

Next, we need to determine the energy required to convert the steam at 0 degrees Celsius to ice at 0 degrees Celsius. The formula for this is:

Q2 = mLf

where:
Q2 is the energy required for phase change from water to ice,
m is the mass of the steam,
Lf is the specific latent heat of fusion for water (334 J/g).

Now, we need to determine the energy required to cool the ice from 0 degrees Celsius to -20 degrees Celsius. We can use the formula:

Q3 = m3 * c2 * ΔT2

where:
Q3 is the energy required to change the temperature of the ice,
m3 is the mass of the ice,
c2 is the specific heat capacity of ice (2.09 J/g°C), and
ΔT2 is the change in temperature (0°C - -20°C).

Finally, the total energy change is the sum of Q1, Q2, and Q3:

Qtotal = Q1 + Q2 + Q3

Let's plug in the values and calculate the energy pressure:

Q1 = (20 g) * (4.18 J/g°C) * (100°C - 0°C)
= 8360 J

Q2 = (20 g) * (334 J/g)
= 6680 J

Q3 = (20 g) * (2.09 J/g°C) * (0°C - -20°C)
= 836 J

Qtotal = 8360 J + 6680 J + 836 J
= 15876 J

Therefore, the energy pressure when 20 grams of steam at 100 degrees Celsius cools to ice at -20 degrees Celsius is 15876 joules.