When 0.9 moles of a mixture of butane, methane, and alkene were passed through bromine water, the mass of the container increased by 16.8 g, and the number of molecules of the gases decreased by 1.5 times. Find the number of atoms in one alkene molecule.
- 12
- 6
- 15
- 9
📝 Detailed explanation
Gas decrease: 0.9 / 1.5 = 0.6 mol remaining.Reacted alkene = 0.9 - 0.6 = 0.3 mol.
Molar mass of alkene = 16.8 g / 0.3 mol = 56 g/mol.
CₙH₂ₙ = 56, so 14n = 56, n = 4.
Formula is C₄H₈.
Total atoms = 4 + 8 = 12.