Graph Interpretation for Rate of a Reaction | Chemistry for Grade 11 (IGCSE) PDF Download

Interpreting Data

• Data recorded during rate studies is utilized for plotting graphs to compute the rate of a reaction
• Graph plotting until the reaction's completion illustrates how the rate alters over time
• As reactants deplete, the reaction rate diminishes, leading the line to become less steep and eventually horizontal, indicating reaction completion
• Multiple runs of a variable can be plotted on a single graph to visualize how it affects the rate; for instance, examining how concentration impacts a reaction involving acid and marble chips
  • For example, plotting the effect of concentration on a reaction between the acid and marble chips

• A steeper curve indicates a faster reaction rate, with the initial steepness indicating the quickest rate at the reaction's outset.
• As the reaction progresses, the decreasing concentration of reactants causes the rate to diminish, reflected by the curve becoming less steep.
• When a reactant is depleted, the reaction halts, the rate becomes zero, and the curve flattens into a horizontal line.
• The quantity of product produced is determined by the limiting reactant: an increase in the limiting reactant leads to a rise in product formation, while an excess reactant does not affect product quantity.
• Drawing a tangent to the slope enables the gradient to be displayed at any point on the curve, indicating the reaction rate.
• The gaseous product's volume reaches a maximum over time, causing the line to plateau, signaling the reaction's completion.
• Given the proportional relationship between volume and mass, this graph could also represent product mass versus time.