Question

When calculating stoichiometric relationships in gas reactions using the combined gas law, why is it important to convert the volumes and pressures to stp

(a) Apply the concept of stoichiometric reactions to theoretical and actual yields.
(b) List three factors that have an impact on the completion of stoichiometric reactions and yields.

Answer 1

When calculating stoichiometric relationships in gas reactions, it is important to convert the volumes and pressures to STP to ensure accurate measurements. Converting to STP allows us to use Avogadro's law and make accurate stoichiometric calculations. Factors that have an impact on the completion of stoichiometric reactions and yields include temperature, pressure, and catalysts.

Step-by-step explanation:

When calculating stoichiometric relationships in gas reactions using the combined gas law, it is important to convert the volumes and pressures to STP (Standard Temperature and Pressure) because STP provides a standard set of conditions for comparison. Converting to STP allows us to use Avogadro's law, which states that equal volumes of gases at the same temperature and pressure contain the same number of particles (molecules or moles). By converting to STP, we can ensure that the gas volumes are measured under the same conditions, allowing us to make accurate stoichiometric calculations.

For example, consider the equation:

2 H2(g) + O2(g) → 2 H2O(g)

The coefficient of 2 in front of H2O(g) indicates that for every 2 moles of H2O(g) produced, 2 moles of H2(g) and 1 mole of O2(g) react. If the volumes and pressures of the gases are not measured at the same conditions, the stoichiometric ratio will not be accurate, leading to incorrect calculations of the reactants and products.

Three factors that have an impact on the completion of stoichiometric reactions and yields are:

1. Temperature: Increasing the temperature can increase the average kinetic energy of gas particles, leading to more frequent and energetic collisions, which increases the reaction rate and can affect the yield.
2. Pressure: Increasing the pressure can decrease the volume of gas particles, which increases the frequency of collisions and can affect the reaction rate and yield.

Catalysts: Catalysts are substances that can speed up a chemical reaction without being consumed in the process. They provide an alternative pathway with lower activation energy, allowing more reactant particles to overcome the energy barrier and participate in the reaction. Catalysts can increase the reaction rate and affect the yield of products.