AlyssaYeh_1B
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How come adding inert gas to a reaction vessel would result in no change to the concentrations of the reactants and products? If nothing changes, what's the effect or purpose of adding the gas then (besides increasing pressure)?

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### Re: Adding inert gas  [ENDORSED]

According to the book, the inert gas increases the total pressure within a reaction vessel. The reacting gases, however, will still occupy the same volume, meaning their concentrations and partial pressures remain the same despite the inert gas. Thus, the introduction of the inert gas has no effect on the equilibrium composition as the moles of reactant and product and volume are constant.

EllieSchmidtke_4I
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Aarja Pavade 1H wrote:According to the book, the inert gas increases the total pressure within a reaction vessel. The reacting gases, however, will still occupy the same volume, meaning their concentrations and partial pressures remain the same despite the inert gas. Thus, the introduction of the inert gas has no effect on the equilibrium composition as the moles of reactant and product and volume are constant.

Would you then have to account for this inert gas when solving equations? Or is it negligible because it is not reacting?

Alice Ma 2K
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EllieSchmidtke_4I wrote:
Aarja Pavade 1H wrote:According to the book, the inert gas increases the total pressure within a reaction vessel. The reacting gases, however, will still occupy the same volume, meaning their concentrations and partial pressures remain the same despite the inert gas. Thus, the introduction of the inert gas has no effect on the equilibrium composition as the moles of reactant and product and volume are constant.

Would you then have to account for this inert gas when solving equations? Or is it negligible because it is not reacting?

You can ignore the inert gas when solving equations. It doesn't react so even if you were to consider it in solving equations, it would cancel out at the end.

Annie Chantasirivisal_4G
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Will helium always be the inert gas we would add, or what other gases could also work?

TimVintsDis4L
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Annie Chantasirivisal_4G wrote:Will helium always be the inert gas we would add, or what other gases could also work?

I'm fairly certain that any inert gas can be added but Helium is the most ideal as it is the least reactive. Helium exists as a single atom so the van der Waals forces are even weaker. This makes it less reactive and the ideal gas to add volume to a container without affecting the reaction.

Chem_Mod
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Helium is an inert gas, but we (as a global society) are actually running out of it, which is a problem. Liquid helium is actually vital for superconducting magnets which are very important in synthetic organic chemistry, and the medical field (MRI scanners). For the purpose of increasing the pressure in a reaction vessel, there are other inert gases that can be used which are a more practical, argon is very common.

Posts: 125
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AlyssaYeh_1B wrote:How come adding inert gas to a reaction vessel would result in no change to the concentrations of the reactants and products? If nothing changes, what's the effect or purpose of adding the gas then (besides increasing pressure)?

Adding an inert gas does not change concentration of the reactants and products because adding that gas does not affect the number of moles (n) and does not affect the volume (v). As concentration is (conc. = n/v) is doesn't change.

Kassidy Ford 1I
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How do you tell which gases are inert gases? is it any gas that doesnt react in the chemical equation?

Chem_Mod
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