To determine the difference in molecular mass between an alkene and an alkyne, let's first take a look at their general formulas.
Alkene: An alkene is a hydrocarbon with at least one double bond between carbon atoms. For an alkene with six carbon atoms, the general formula is CnH2n. Therefore, for 6 carbon atoms, the molecular formula is C6H12.
Alkyne: An alkyne is a hydrocarbon with at least one triple bond between carbon atoms. For an alkyne with six carbon atoms, the general formula is CnH2n-2. Therefore, for 6 carbon atoms, the molecular formula is C6H10.
Now let's calculate the molecular masses:
Molecular mass of alkene (C6H12):
- Carbon (C): 6 atoms x 12 g/mol = 72 g/mol
- Hydrogen (H): 12 atoms x 1 g/mol = 12 g/mol
- Total for C6H12 = 72 g/mol + 12 g/mol = 84 g/mol
Molecular mass of alkyne (C6H10):
- Carbon (C): 6 atoms x 12 g/mol = 72 g/mol
- Hydrogen (H): 10 atoms x 1 g/mol = 10 g/mol
- Total for C6H10 = 72 g/mol + 10 g/mol = 82 g/mol
The **difference** in molecular mass between the alkene and alkyne is **84 g/mol - 82 g/mol** = 2 g/mol.