1. Laboratory Bench
2. Experimental Parameters
3. Live Data Table
| Time (s) | Vol $O_2$ ($cm^3$) | Rate ($cm^3/s$) |
|---|---|---|
| Press "Start Run" to record data... | ||
4. Oxygen Volume vs. Time Graph
Leaving Certificate Chemistry Exam Analysis
Interactive self-check questions based on practical exam questions.
Why is the slope of the graph steepest at the start ($t = 0$)?
Think about reactant concentrations and collision theory.
At $t = 0$, the concentration of $H_2O_2$ is at its maximum. Therefore, the frequency of effective collisions between reactant molecules and the catalyst surface is highest, producing the maximum initial reaction rate.
What function does $MnO_2$ perform in this reaction?
Role of heterogeneous catalyst in decomposition.
$MnO_2$ acts as a heterogeneous catalyst. It lowers the activation energy ($E_a$) by providing an alternative reaction pathway, increasing the rate of decomposition without being chemically consumed in the reaction.
How can you tell from the graph when the reaction is complete?
Curve leveling off observation.
The reaction is complete when the graph becomes completely horizontal (slope = 0). This indicates that no further $O_2$ gas is being produced because all $H_2O_2$ has fully reacted.