Final answer:
Using stoichiometry and the law of conservation of mass, the maximum mass of ethylene produced from 20 g of ethane is less than 20 g, considering the molar masses of ethane and ethylene.
Step-by-step explanation:
The question involves the pyrolysis of ethane to produce ethylene, which is an example of a chemical reaction. Using stoichiometry, we can solve for the maximum mass of ethylene produced from 20 g of ethane.
The balanced chemical equation is C₂H₆ ⟶ C₂H₄ + H₂. Considering that no atoms are lost or gained during a chemical reaction and the law of conservation of mass, the total mass of products will be equal to the total mass of reactants.
The molar mass of ethane (C₂H₆) is approximately 30 g/mol, and the molar mass of ethylene (C₂H₄) is about 28 g/mol. If starting with 20 g of ethane:
- Convert the mass of ethane to moles: 20 g / 30 g/mol = 0.67 moles of C₂H₆.
- Use the stoichiometry of the reaction to find moles of C₂H₄ produced, which will be the same (1:1 ratio).
- Convert the moles of ethylene to mass: 0.67 moles * 28 g/mol = 18.76 g of C₂H₄.
Thus, the maximum mass of ethylene produced will be less than 20 g, so the correct answer is (c) Less than 20 g.