Calculate the enthalpy change per gram for the combustion of ethane (C2H6(g)).
Calculate the enthalpy of reaction for H2(g) + C2H4(g) → C2H6(g).
[ΔH°f(C2H4(g)) = 52.3 kJ/mol; ΔH°f(C2H6(g)) = –84.7 kJ/mol]
–137 kJ/mol
To calculate the enthalpy change per gram for the combustion of ethane (C2H6(g)), we need to know the enthalpy of the combustion reaction and the molar mass of ethane.
1. Enthalpy of the combustion reaction: The balanced equation for the combustion of ethane is:
C2H6(g) + 7/2 O2(g) → 2CO2(g) + 3H2O(g)
The enthalpy change for this reaction can be found in a reference book or online database. Let's assume it is -1560 kJ/mol. This means that for every mole of ethane combusted, 1560 kJ of energy is released.
2. Molar mass of ethane: The molar mass of ethane (C2H6) can be calculated by adding up the atomic masses of each element in the compound. The atomic mass of carbon (C) is 12.01 g/mol, and the atomic mass of hydrogen (H) is 1.01 g/mol.
So, the molar mass of ethane is:
2(12.01 g/mol) + 6(1.01 g/mol) = 30.07 g/mol
3. Calculate the enthalpy change per gram: Now we can calculate the enthalpy change per gram of ethane.
Enthalpy change per mole = -1560 kJ/mol
Molar mass of ethane = 30.07 g/mol
Enthalpy change per gram = (Enthalpy change per mole / Molar mass of ethane) * 1 gram
Plugging in the values, we get:
(1560 kJ/mol / 30.07 g/mol) * 1 g = 51.9 kJ/g
Therefore, the enthalpy change per gram for the combustion of ethane is 51.9 kJ/g.
To calculate the enthalpy change per gram for the combustion of ethane (C2H6(g)), we need to know the enthalpy change of the combustion reaction. The balanced equation for the combustion of ethane is:
C2H6(g) + 7/2 O2(g) → 2 CO2(g) + 3 H2O(g)
The given enthalpy change of the combustion reaction is typically provided in kilojoules per mole (kJ/mol). To convert it to kJ/gram, we need to find the molar mass of ethane, which is 30.07 g/mol.
Let's assume that the enthalpy change of the combustion of ethane is -1559 kJ/mol.
To calculate the enthalpy change per gram, we can use the following steps:
1. Calculate the moles of ethane (C2H6):
- Mass of ethane = 1 gram
- Moles of ethane = Mass of ethane / Molar mass of ethane
- Moles of ethane = 1 g / 30.07 g/mol
2. Calculate the enthalpy change per mole of ethane:
- Enthalpy change per mole = Given enthalpy change of combustion
3. Calculate the enthalpy change per gram:
- Enthalpy change per gram = Enthalpy change per mole / Moles of ethane
Let's do the calculations:
1. Moles of ethane = 1 g / 30.07 g/mol ≈ 0.0333 mol
2. Enthalpy change per mole = -1559 kJ/mol
3. Enthalpy change per gram = -1559 kJ/mol / 0.0333 mol ≈ -46782 kJ/g
Therefore, the enthalpy change per gram for the combustion of ethane is approximately -46782 kJ/g.