The molar heat of vaporization of water is 42 kJ/mol. How much energy is released by the condensation of 3.0 g of
water?
How many mols is 3 g H2O?
mols = g/molar mass = 3/18 = 0.168 mols.
42 kj/mol x 0.168 mol = ? kJ released. Energy going out is negative.
wagwan fam
To find out how much energy is released by the condensation of 3.0 g of water, we need to use the molar heat of vaporization and convert grams to moles.
Here's how you can approach this problem:
1. Determine the molar mass of water (H2O). The molar mass can be found by adding the atomic masses of each element in the compound. The atomic masses of hydrogen (H) and oxygen (O) are approximately 1 g/mol and 16 g/mol, respectively. Therefore, the molar mass of water is 18 g/mol.
2. Convert the given mass of water (3.0 g) to moles. We can use the equation:
Moles = Mass / Molar mass
Substituting the values:
Moles = 3.0 g / 18 g/mol
Moles ≈ 0.167 mol
3. Now that we have the number of moles of water, we can determine the energy released by the condensation using the molar heat of vaporization. The molar heat of vaporization of water is given as 42 kJ/mol.
Energy released = Moles of water × Molar heat of vaporization
Substituting the values:
Energy released = 0.167 mol × 42 kJ/mol
Energy released ≈ 7 kJ
Therefore, approximately 7 kJ of energy is released by the condensation of 3.0 g of water.