Calculate the energy change when 50.0 g of water evaporates (Hyap = 2250 kJ/g). Molar mass for water 18 g/mol
in simple steps
To calculate the energy change when 50.0 g of water evaporates, we can use the formula:
Energy change = mass * heat of vaporization
First, let's convert the mass of water from grams to moles using the molar mass of water (18 g/mol):
50.0 g / 18 g/mol = 2.78 mol
Now, let's calculate the energy change using the heat of vaporization (Hyap) and the number of moles:
Energy change = 2.78 mol * 2250 kJ/g
To cancel out grams, we need to convert grams to kilograms:
50.0 g = 50.0 g * (1 kg / 1000 g) = 0.05 kg
Now, calculate the energy change:
Energy change = 2.78 mol * 2250 kJ/g * 0.05 kg
Energy change = 312.75 kJ
To calculate the energy change when 50.0 g of water evaporates, we need to use the heat of vaporization (Hyap) and the molar mass of water.
Step 1: Convert the mass of water from grams to moles.
- Use the molar mass of water (H2O) to convert grams to moles.
- Molar mass of water (H2O) = 18 g/mol.
- Number of moles = Mass (g) / Molar Mass (g/mol).
- Number of moles = 50.0 g / 18 g/mol = 2.7778 mol (rounded to four decimal places).
Step 2: Calculate the energy change using the heat of vaporization (Hyap).
- Heat of vaporization (Hyap) = 2250 kJ/g.
- Energy change = Number of moles * Heat of vaporization.
- Energy change = 2.7778 mol * 2250 kJ/g.
Step 3: Convert the energy change to kilojoules (kJ).
- Since the heat of vaporization is in kJ per gram, the result is already in kJ.
- No conversion is needed.
Step 4: Calculate the final energy change.
- Multiply the number of moles by the heat of vaporization.
- Energy change = 2.7778 mol * 2250 kJ/g = 6269.5 kJ (rounded to one decimal place).
Therefore, the energy change when 50.0 g of water evaporates is approximately 6269.5 kJ.
To calculate the energy change when water evaporates, you can follow these simple steps:
Step 1: Convert the mass of water from grams to moles.
Given that the molar mass of water is 18 g/mol and the mass of water is 50.0 g, we can use the formula:
moles of water = mass of water / molar mass of water
moles of water = 50.0 g / 18 g/mol
moles of water = 2.78 mol (rounded to two decimal places)
Step 2: Calculate the energy change by multiplying the moles of water by the heat of vaporization.
Given the heat of vaporization (Hyap) of water is 2250 kJ/g, we need to convert it to kJ/mol.
Heat of vaporization in kJ/mol = Hyap * molar mass of water
Heat of vaporization in kJ/mol = 2250 kJ/g * 18 g/mol
Heat of vaporization in kJ/mol = 40500 kJ/mol
Now, we can calculate the energy change:
Energy change = moles of water * heat of vaporization
Energy change = 2.78 mol * 40500 kJ/mol
Energy change = 112590 kJ
So, the energy change when 50.0 g of water evaporates is approximately 112590 kJ.