How much heat in kilojoules is evolved in converting 1.00 mol of steam at 145 Celsius to ice at -50 Celsius?
See my response above.
To calculate the heat evolved in converting steam at 145 degrees Celsius to ice at -50 degrees Celsius, we need to consider two steps:
1. Calculating the heat released in cooling the steam from 145°C to 0°C.
2. Calculating the heat released in converting the cooled steam at 0°C to ice at -50°C.
Let's break down each step and calculate the respective heats.
Step 1: Cooling steam from 145°C to 0°C.
To calculate the heat released during this step, we need to use the specific heat capacity of water (steam) and the equation:
q = m * C * ΔT
Where:
q is the heat released
m is the mass of the substance (here, steam)
C is the specific heat capacity
ΔT is the change in temperature
The specific heat capacity of water/steam is roughly 4.18 J/g°C.
1. Convert the given temperature values to Kelvin:
T1 = 145°C + 273.15 = 418.15 K
T2 = 0°C + 273.15 = 273.15 K
2. Calculate the heat released in cooling the steam using the equation above:
q1 = (1.00 mol) * (18.02 g/mol) * (4.18 J/g°C) * (418.15 K - 273.15 K)
Step 2: Converting cooled steam at 0°C to ice at -50°C.
Here, the heat released is the heat of fusion (the energy required to convert a substance from one state to another at a constant temperature).
The heat of fusion for water is approximately 334 J/g.
1. Convert the given temperature values to Kelvin:
T1 = 0°C + 273.15 = 273.15 K
T2 = -50°C + 273.15 = 223.15 K
2. Calculate the heat released in converting the cooled steam to ice using the equation:
q2 = (1.00 mol) * (18.02 g/mol) * (334 J/g)
Finally, to calculate the total heat evolved, add the two calculated heats together:
Total heat evolved = q1 + q2
Note: The specific heat capacity and heat of fusion values used are approximate averages and may vary slightly depending on the source. Also, the specific heat capacity and heat of fusion values given here are in joules. To convert them to kilojoules, divide the result by 1000.