Pressure changes play a big role in how gases react when they are in balance, especially in factories. This idea comes from something called Le Chatelier's principle.

1. Le Chatelier's Principle: This principle says that if a system at balance (equilibrium) experiences a change in pressure, it will adjust in a way that tries to balance things out again.

2. Effect of Pressure: When it comes to reactions with gases, increasing the pressure makes the side with fewer gas molecules more likely to form. For example, in this reaction:

   $aA(g) + bB(g) \rightleftharpoons cC(g) + dD(g)$

   • If the total number of gas molecules on the left side (a + b) is greater than on the right side (c + d), then adding pressure will help create more products.

3. Industrial Applications: Take the Haber process, which is used to make ammonia ($N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$). By increasing the pressure to around 200 atmospheres, the process produces more ammonia. It can increase efficiency by about 10% for every 100 atmospheres of pressure added.

4. Equilibrium Constants: The balance constant ($K_p$) for reactions involving gases changes when the pressure changes. This affects how many products and reactants are present.

Optimizing pressure is really important in factories. It helps them produce more while keeping costs low in chemical production.