How to calcualte the enthalpy change for the process in which 6.00g of steam at 100C is coverted to liquid water at a temperature of 35.0?
To calculate the enthalpy change for the process of converting steam to liquid water, you need to consider several steps.
Step 1: Calculate the heat absorbed by the steam as it cools down from 100°C to 35.0°C.
To do this, you need to know the specific heat capacity (C) of steam and the mass of the steam.
The specific heat capacity of steam is approximately 2.03 J/g°C, and the mass of the steam is given as 6.00 g.
The formula to calculate the heat absorbed is:
Heat absorbed = mass × specific heat capacity × temperature change
Temperature change = final temperature - initial temperature
So, let's calculate the heat absorbed by the steam:
Temperature change = 35.0°C - 100°C = -65.0°C
Heat absorbed = 6.00 g × 2.03 J/g°C × (-65.0°C)
Step 2: Calculate the heat released when the steam condenses into liquid water at 100°C.
Water releases heat when it undergoes a phase change from a gas to a liquid, which is called the heat of condensation.
The heat of condensation for steam is approximately -40.7 kJ/mol. To convert this to joules per gram, you need to know the molar mass of water, which is around 18.02 g/mol.
Heat released = heat of condensation × moles of water
Moles of water = mass of water / molar mass of water
Mass of water = mass of steam = 6.00 g
So, let's calculate the heat released when the steam condenses:
Moles of water = 6.00 g / 18.02 g/mol
Heat released = -40.7 kJ/mol × moles of water
Step 3: Calculate the total enthalpy change.
Since the heat absorbed and the heat released are in opposite directions, you can simply add them together to obtain the total enthalpy change.
Total enthalpy change = Heat absorbed + Heat released
Now, you can substitute the calculated values into the equation and find the answer.