## Reaction Quotient

$PV=nRT$

TiffanyL1G
Posts: 61
Joined: Fri Sep 28, 2018 12:22 am

### Reaction Quotient

Why is it that when solving for Q, the reaction quotient, we disregard the solids and the liquids in the chemical equation? I think we disregard solids because it isn’t possible to find the concentration of a solid but why do we disregard liquids?

Noah Fox 1E
Posts: 31
Joined: Fri Sep 28, 2018 12:20 am

### Re: Reaction Quotient

Because they do not affect the concentrations of reactants and products, liquids are not taken into account for equilibrium reactions. That being said H2O undergoes a acid base reaction with itself when it produces hydrogen ions and hydroxide ions spontaneously, but it goes disregarded because water naturally stabilizes at 7 ph.

RachelCheung1A
Posts: 30
Joined: Fri Sep 28, 2018 12:19 am

### Re: Reaction Quotient

We disregard solids and liquids because their concentrations are the same throughout the reaction. Concentration equals to density divided by molar mass and both solids and liquids' densities are pretty much constant, therefore concentrations of solids and liquids are constant.

Aili Ye 4L
Posts: 58
Joined: Fri Sep 28, 2018 12:16 am

### Re: Reaction Quotient

We don't include liquids and solids because by convention the values in the K expression change over time, and the concentration of liquids and solids do not change.

fgalasso1b
Posts: 32
Joined: Wed Oct 03, 2018 12:15 am

### Re: Reaction Quotient

Both solids and liquids are pure so they don't have a concentration. Having no concentration means they are not included in the calculations of K or Q.

fgalasso1b
Posts: 32
Joined: Wed Oct 03, 2018 12:15 am

### Re: Reaction Quotient

Both solids and liquids are pure so they don't have a concentration. Having no concentration means they are not included in the calculations of K or Q.

Charles Gu 1D
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

### Re: Reaction Quotient

Since solids and liquids concentrations will not change, they will be eventually canceled out. Therefore, they are not included.