Concentrations

[BriannaDis2C]

Dr. Lavelle mentioned during today’s lecture that concentrations must be positive values. Out of curiosity, why do they have to be positive? Is it not possible for the concentration to dissipate or weaken?

[Austin_Schwartz_1L]

Hello,
Concentrations must be positive because they represents quantities of substances, and you can not have a negative amount of something. If they represented the rates at which the concentrations are changing, then it could be negative, but that it not the case.
I hope this helps!

[Simone Byun 1F]

Concentrations measure the quantity of something, which cannot be negative. Also, if we think of concentration as mol/volume, neither mol nor volume can be negative either. So concentration would not be negative.

[Shay Crookall 2L]

Can't have a negative amount of a substance! I like what Simone said about mol and volume, makes it super clear to understand. :)

[005493723]

You can have lower concentrations but you cannot have a negative amount of the substance, the lowest possible value would be zero meaning that it is not present in the solution.

[Emily Wu 2G]

if the concentration is negative, there would be no substance.

[Jessica Sun 2I]

a negative concentration would mean there is less than 0 moles which is not possible. The sign is not an indication of change in concentration but the actual quantity itself.

[Anjali Kalagiri 3F]

Concentration represents moles/volume. For concentration to be negative there would have to be negative moles or negative volume which is impossible.

[205678283]

Concentration is an amount of a substance. Think about the formula M=n mols/L liters. We learned that mols measures the amount of any substance with Avogrados number 6.022 x 10^32. This could be measuring mols of Magnesium Chloride or mols of m&ms. Either way, you cannot have negative amounts of Magnesium Chloride or m&ms, so concentration is always positive.

[605499821]

Concentrations have to have a positive value.

[Kiana Rogers 1E]

It isn't possible for concentration values to be negative.

[Amaris Cagungun 1F]

Concentrations must be positive because a negative concentrations means there is negative moles which is not possible.