Answer:
3CH₄ + 3N₂Cl₄ → 3CCl₄ + 3N₂ + 6H₂
Explanation:
Carbon_black sphere
Nitrogen_blue sphere
Chlorine_green sphere
Hydrogen_white sphere
Reactants:
Three molecules that contain one black sphere and four white spheres
3CH₄
Three molecules that contain two blue spheres and four green spheres:
3N₂Cl₄
Products:
Three molecules that contain one black sphere and four green spheres:
3CCl₄
Three molecules that contain two blue spheres:
3N₂
Six molecules that contain two white spheres
6H₂
The reaction proper:
3CH₄ + 3N₂Cl₄ → 3CCl₄ + 3N₂ + 6H₂
Sidenote: I hope this answer helps!