Answer:
Here are two changes to a practical that could increase the mean time taken to collect 20 cm of gas:
Explanation:
Here are two changes to a practical that could increase the mean time taken to collect 20 cm of gas:
1. Decrease the reaction rate:
Use a less concentrated reactant solution: If the reactants are less concentrated, the collisions between them will be less frequent, slowing down the reaction and extending the time it takes to reach 20 cm of gas.
Change the temperature: Lowering the temperature usually reduces the kinetic energy of molecules, leading to fewer successful collisions and a slower reaction rate.
Introduce an inhibitor: Adding a substance that hinders the reaction's progress by blocking active sites or interfering with other necessary steps will slow down the gas production.
2. Increase the gas solubility in the reaction medium:
Use a different solvent: If the gas produced is more soluble in the chosen solvent, it will tend to dissolve back into the solution instead of escaping as a gas, ultimately requiring a longer time to reach 20 cm in the collection vessel.
Lower the agitation: Stirring or shaking the reaction mixture can encourage the bubbles to escape the solution more readily. Reducing the agitation allows the gas to stay dissolved for a longer duration, delaying the time it takes to reach the desired volume.
Remember, the specific changes that will most effectively increase the mean time for gas collection depend on the details of the practical, such as the type of reaction, the gas being produced, and the equipment used.
It's also important to consider the desired outcome of the practical. While increasing the time may be the objective in some cases, it might be undesirable in others where efficiency and speed are prioritized.
I hope this helps!
