The heat of vaporization of liquid water at 373 K is 40.7 kJ/mol. The value of the enthalpy change when 2.00 g of steam condenses at 373 K is?
To find the enthalpy change when 2.00 g of steam condenses at 373 K, you can use the formula:
Enthalpy change = Heat of vaporization × Number of moles
First, we need to find the number of moles of steam:
Number of moles = mass / molar mass
The molar mass of water (H2O) is approximately 18.015 g/mol.
Number of moles = 2.00 g / 18.015 g/mol = 0.11095 mol
Now, we can calculate the enthalpy change:
Enthalpy change = Heat of vaporization × Number of moles
Enthalpy change = 40.7 kJ/mol × 0.11095 mol
Enthalpy change = 4.512 kJ
Therefore, the value of the enthalpy change when 2.00 g of steam condenses at 373 K is approximately 4.512 kJ.
To find the enthalpy change when 2.00 g of steam condenses at 373 K, we need to use the equation:
∆H = (heat of vaporization) x (number of moles)
First, we need to determine the number of moles of steam. We can use the molar mass of water to convert grams to moles.
The molar mass of water (H2O) is calculated by summing up the atomic masses of its constituent elements: hydrogen and oxygen.
Molar mass of hydrogen (H) = 1.008 g/mol
Molar mass of oxygen (O) = 15.999 g/mol
Molar mass of water (H2O) = (2 x molar mass of hydrogen) + molar mass of oxygen
= (2 x 1.008 g/mol) + 15.999 g/mol
= 18.015 g/mol
Now, we can calculate the number of moles of steam using the formula:
Number of moles = mass / molar mass
Number of moles of steam = 2.00 g / 18.015 g/mol
≈ 0.1109 mol
Next, we can use the heat of vaporization and the number of moles to calculate the enthalpy change:
∆H = (heat of vaporization) x (number of moles)
= 40.7 kJ/mol x 0.1109 mol
≈ 4.51 kJ
Therefore, the enthalpy change when 2.00 g of steam condenses at 373 K is approximately 4.51 kJ.