Answer:
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
Step-by-step explanation:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
3H₂O → 3H₂ + 3O₂
This equation do not follow the law of conservation of mass because there are more oxygen atoms on right side so mass is not conserved.
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
This equation follow the law of conservation of mass because there are equal number of atoms of all elements on both side of equation.
C + 4H₂ → CH₄
This equation do not follow the law of conservation of mass because there are more hydrogen atoms on left side of equation so mass is not conserved.
2Na + Cl → NaCl
This equation also do not follow the law of conservation of mass because there are more sodium atoms on left side of equation so mass is not conserved.