Last Question from Lesson 6.2 material. Again, using the Haber Process, determine which hypotheses could be "supported" and which would be "rejected" by the direct observations that resulted in this graph.

Question

Each model hypothesis will only fit into one category. Here is the graph again to help you.
Accept Hypothesis Reject Hypothesis
Percentage yield will increase if pressure is increased and temperature is decreased.

As pressure increases, percentage yield of ammonia increases because the number of particles collisions increase.

Increasing temperature and decreasing pressure will result in higher ammonia production.

Increasing ammonia production requires an increase in temperature.

Answer 1

To determine which hypotheses could be "supported" or "rejected" by the direct observations from the Haber Process graph, we will analyze each hypothesis based on the principles of the Haber Process and typical observations regarding temperature, pressure, and yield.

1. Percentage yield will increase if pressure is increased and temperature is decreased.

   • Accept Hypothesis: This aligns with the principles of the Haber process, where higher pressure generally favors production of ammonia. Lower temperatures favor the exothermic reaction but can slow the rate of reaction. Given that the query states an increase in pressure and decrease in temperature, while this can support the yield, it's conditional and could be viewed more cautiously based on the context.

2. As pressure increases, percentage yield of ammonia increases because the number of particles collisions increase.

   • Reject Hypothesis: While it's true that increasing pressure typically increases yield (due to shift in equilibrium favoring products), attributing this solely to an increase in the number of particle collisions is misleading. Yield increases are more directly related to the position of equilibrium rather than just collision frequency.

3. Increasing temperature and decreasing pressure will result in higher ammonia production.

   • Reject Hypothesis: Higher temperatures shift the equilibrium back towards reactants for the exothermic reaction, likely leading to a lower yield of ammonia. Decreasing pressure also favors the reactants. Therefore, this hypothesis is inconsistent with the expected observations.

4. Increasing ammonia production requires an increase in temperature.

   • Reject Hypothesis: In the context of the Haber process, while increasing temperature increases the rate of reaction, it does not favor ammonia production because the formation of ammonia is exothermic, and increasing temperature actually shifts the equilibrium left towards reactants.

To summarize:

Accept Hypothesis:

• Percentage yield will increase if pressure is increased and temperature is decreased.

Reject Hypothesis:

• As pressure increases, percentage yield of ammonia increases because the number of particles collisions increase.
• Increasing temperature and decreasing pressure will result in higher ammonia production.
• Increasing ammonia production requires an increase in temperature.