Q regarding non-equilibrium systems (1 Viewer)

[amdspotter]

If possible can someone explain how they would answer this question,
"Explain why combustion and photosynthesis are examples of non-equilibrium reactions. Include an equation in your answer. "

 

[jazz519]

For equations just pick any fuel for combustion like octane (C8H18) for example. Photosynthesis is an equation you have to memorise.

Whether a reaction is irreversible or reversible depends mostly on the activation energy (the minimum collisional energy required for a collision to break bonds, so the reaction occurs) of the forward and reverse reactions. In reactions like combustion and photosynthesis, the reverse activation energy to convert the products back to the reactants is very high. Therefore the reverse process does not occur as too much energy is needed and this means it is a non-equilibrium system, where only the forward reaction occurs.

Maybe good idea to include a diagram as well of the energy profile, but this and other details will depend on how marks the question is

 

[amdspotter]

For equations just pick any fuel for combustion like octane (C8H18) for example. Photosynthesis is an equation you have to memorise.

Whether a reaction is irreversible or reversible depends mostly on the activation energy (the minimum collisional energy required for a collision to break bonds, so the reaction occurs) of the forward and reverse reactions. In reactions like combustion and photosynthesis, the reverse activation energy to convert the products back to the reactants is very high. Therefore the reverse process does not occur as too much energy is needed and this means it is a non-equilibrium system, where only the forward reaction occurs.

Maybe good idea to include a diagram as well of the energy profile, but this and other details will depend on how marks the question is

oh ok that makes sense, also both the photosynthesis and combustion part combined is 5 marks. also can you quickly define the term non-equilibrium, as my confusion kinda stems from that.

 

[jazz519]

oh ok that makes sense, also both the photosynthesis and combustion part combined is 5 marks. also can you quickly define the term non-equilibrium, as my confusion kinda stems from that.

Equilibrium is referring to a reversible reaction (one with double arrow)

Non-equilibrium is referring to a irreversible reaction (only has forward arrow). This is essentially your complete reaction or standard reaction you learnt about throughout Year 11

 

[amdspotter]

Equilibrium is referring to a reversible reaction (one with double arrow)

Non-equilibrium is referring to a irreversible reaction (only has forward arrow). This is essentially your complete reaction or standard reaction you learnt about throughout Year 11

Ah ok this makes sense, idk y but I began to believe that non equilibrium is different to irreversible. Thanks a lot m8 U cleared up all my confusion, really appreciate it