Question

Systems that have gaseous reactants and products behave a little bit differently when an experimenter works to force the system out of equilibrium in order to obtain a product. The mechanism of stress that is used is "pressure". [If you need to review this concept a little bit it can be found in Lesson 7.4 - Changing Reaction Rates. Guided notes might help support you, or even reviewing Unit 6 Rates of Reaction Lesson 2 a little bit. --- I am certain you can work through this!] Added pressure, or force exerted over area, can increase the number of collisions among particles in a closed system. Hopefully this makes sense. The system works to balance numbers of 'moles' of reactant(s) and product(s) throughout. We can find the number of moles by BALANCING the EQUATION. Here is our example from the Haber-Bosch process we used in Unit 6 portfolio work. It explains 'why' the reaction is more efficient at lower temperatures. N2(g) + 3H2(g) ⇌ 2NH3 (g) + heat energy nitrogen gas + hydrogen gas react reversibly to form ammonia gas + heat Please use the image above to help you count moles of reactants and products to determine which direction the shift will take the experimenter under the conditions applied. The equation is balanced for you. (6 points) Forward Reaction (shift right) Reverse Reaction (shift left) The experimenter ADDS heat to the closed system. The experimenter counts 2 moles of nitrogen and 6 moles of hydrogen gas in the closed system. The experiment counts 8 moles of ammonia in the closed system. The experimenter counts 1 mole of ammonia in the closed system. The experimenter ADDS the catalyst of iron to break the triple covalent bonds in nitrogen gas. [Check Lesson 7.4 for help if needed!] The experimenter REMOVES heat from the closed system. Skip to navigation they all nedd one answer for all

Answer 1

In the context of the Haber-Bosch process given by the reaction:

\[ \text{N}_2(g) + 3\text{H}_2(g) ⇌ 2\text{NH}_3(g) + \text{heat} \]

let’s analyze the shifts in equilibrium based on the changes made by the experimenter.

1. Experimenter ADDS heat to the closed system.

   • When heat is added to an exothermic reaction (like this one, where the reaction produces heat), the equilibrium will shift to the left (reverse reaction). The system will attempt to absorb the excess heat by using it to convert products (ammonia) back into reactants (nitrogen and hydrogen).

2. The experimenter counts 2 moles of nitrogen and 6 moles of hydrogen gas in the closed system.

   • Total moles of reactants: 2 (N₂) + 6 (H₂) = 8 moles
   • Total moles of products: 8 moles of ammonia. Since there are more moles of reactants than products in this case, any disturbance that increases pressure or decreases volume could favor the production of ammonia (product) over the reactants.

3. The experiment counts 8 moles of ammonia in the closed system.

   • This indicates a significant amount of product is present, which may shift the reaction to the left (reverse reaction) if additional pressure does not favor the production of products.

4. The experimenter counts 1 mole of ammonia in the closed system.

   • With fewer products present, the system may naturally shift right to produce more ammonia, depending on the other equilibrium conditions.

5. The experimenter ADDS the catalyst of iron to break the triple covalent bonds in nitrogen gas.

   • Adding a catalyst accelerates the rate of both the forward and reverse reactions equally but does not affect the position of the equilibrium. Therefore, there would be no shift in either direction.

6. The experimenter REMOVES heat from the closed system.

   • Removing heat from an exothermic reaction will shift the equilibrium to the right (forward reaction) as the system seeks to produce more heat by favoring the formation of products (ammonia).

Summary of Shifts:

• Adding heat → shift left (reverse reaction)
• Increasing pressure with more moles of reactants present → Can favor forward reaction
• Presence of 1 mole of ammonia → Potentially favors forward reaction
• Adding catalyst → No shift
• Removing heat → shift right (forward reaction)

This analysis provides insight into how various modifications affect the equilibrium position in the reaction.