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1) what is the difference between (delta)rH and (delta)rH-? 2)N2 + 3H2 <----> 2NH3. What are the conditions for maximum yield of NH3?

•  High pressure: An increase in pressure will favour the side with the fewest molecules so more ammonia will be produced
• Low temperature: The forward reaction (production of ammonia) is exothermic so a decrease in temperature will reuslt in more ammonia production.
• Catalyst: An iron catalyst lowers the activation energy so more reactants can form the product (ammonia).
• Increase in reactant concentration: There is a greater proportion of nitrogen and hydrogen than there is ammonia so more product will be produced.
• Decrease in product concentration (ie, siphon off the ammonia): There will be a smaller proportion of ammonia compared to reactants so more ammonia wil be produced to compensate.