Q. For which reaction is 6CO2 6H2O → C6H12O6 6O2 the correct equation

The equation 6CO2 + 6H2O → C6H12O6 + 6O2 is the correct overall chemical equation for photosynthesis, the light-dependent process by which autotrophic organisms (primarily green plants, algae, and cyanobacteria) convert inorganic carbon dioxide and water into organic glucose and oxygen. This equation specifically represents oxygenic photosynthesis—the type that produces oxygen as a byproduct and occurs in chloroplasts where chlorophyll captures light energy to drive the reaction. While the equation shows a simple one-step conversion, it actually summarizes dozens of individual reactions occurring in two main phases: the light reactions and the Calvin cycle.

This equation is not correct for cellular respiration (which runs in the opposite direction), fermentation, chemosynthesis, or any other metabolic pathway. It specifically describes the anabolic process where light energy is converted into chemical energy stored in glucose bonds, making it the foundation of nearly all food chains and the source of atmospheric oxygen. The equation's directionality—moving from simple inorganic molecules to complex organic ones—and its requirement for energy input (implied but not shown) distinguish it from catabolic processes like respiration. When answering which reaction this equation represents, the only correct answer is photosynthesis, and more precisely, the light-dependent synthesis of glucose from carbon dioxide and water that occurs in photosynthetic organisms.