What controls the rate of a chemical reaction?
Reaction rate measures how quickly reactant or product amounts change over time. A reaction being energetically possible does not mean it proceeds rapidly under everyday conditions. Rate depends on molecular mechanisms and experimental conditions.
Temperature, concentration, and surface area
Higher temperature generally increases the fraction of particles able to cross an activation barrier. Concentration or gas pressure can affect collisions, but the precise dependence follows an experimentally determined rate law. Surface area matters in heterogeneous reactions, making powders behave differently from large pieces. Stirring may improve material transport without necessarily changing the intrinsic rate constant.
Catalysis and fair comparison
A catalyst can accelerate a reaction by providing an alternative mechanism, without changing its equilibrium constant or overall energy difference. Comparing rates requires controlled temperature, concentration, amount, and measurement method. Apparent gas release can also depend on gas solubility and vessel geometry. Observations should therefore be converted into measurable quantities, with individual variables investigated under controlled conditions.