Ethane, C2H6, has a molar heat of vaporization of 15kJ/mole. How many kilojoules or energy are required to vaporize 5 g of ethane?
mols ethane = grams/molar mass = ?
q = ? mols ethane x heat vap
To find the amount of energy required to vaporize a given mass of ethane, you need to follow these steps:
1. Determine the molar mass of ethane, C2H6:
- The molar mass of carbon (C) is approximately 12.01 g/mol, and hydrogen (H) is approximately 1.01 g/mol.
- Therefore, the molar mass of ethane (C2H6) is calculated as follows:
Molar mass of ethane = (2 * molar mass of carbon) + (6 * molar mass of hydrogen)
= (2 * 12.01 g/mol) + (6 * 1.01 g/mol)
= 24.02 g/mol + 6.06 g/mol
= 30.08 g/mol
2. Convert the given mass of ethane to moles:
- Given mass of ethane = 5 g
- To convert grams to moles, you divide the mass by the molar mass:
Moles of ethane = mass of ethane / molar mass of ethane
= 5 g / 30.08 g/mol
= 0.166 moles (rounded to 3 decimal places)
3. Calculate the energy required to vaporize the moles of ethane:
- Given molar heat of vaporization = 15 kJ/mol
- To calculate the energy required, you multiply the moles by the molar heat of vaporization:
Energy = moles of ethane * molar heat of vaporization
= 0.166 moles * 15 kJ/mol
= 2.49 kJ (rounded to 2 decimal places)
Therefore, it requires approximately 2.49 kilojoules of energy to vaporize 5 grams of ethane.