Question

Why don't we ever specify the conc of bases in the laboratory? Why only con or dil HCl. Why never con or dil NaOH or NH4OH?

Answer 1

Because HCl is a fairly strong acid.
"Concentrated" hydrochloric acid will contain many molecules of hydrochloric acid in a given volume of water. A dilute acid is one that is not very concentrated. You can make an acid solution more dilute by adding water.

I think it is also referring to it's ability to donate it's proton (hydrogen). You'd want a concentrated acid to react with an alcohol to make it a weaker base. A common acid-base reaction in organic chemistry.

Answer 2

yes, but why not for bases? if we consider a weak base, by Oswald's dilution law, even its degree dissociation will change with its concentration, right?

Answer 3

Most acids have a maximum concentration at a specified temperature.
It means any excess would evaporate from the solution.

These solution are called concentrated.
This is why you will not find any hydrochloric acid with a mass % greater than 36%.

Diluted, if not specified, means half that concentration, ie 18%.
So "diluted" in this sense is still a very concentrated solution of HCl.

Bases such as NaOH are solid crystals and can be stored as such, as put in solution when needed.

Answer 4

Okay, but I could still vary the amount of solid base that I add to a specific amt of water and vary its concentration, right? Why doesn't that affect it's action?

Answer 5

just accept it.

Answer 6

Oh, I get it now, thanks @Vincent-Lyon.Fr

Answer 7

The main idea is: all compounds that you can store and handle easily in their solid form do not need to be kept as "concentrated" or "diluted" solutions, that would need more space.

Compounds that, pure, are viscous liquid or gases are much more difficult to store. It is easier to dissolve them in water and keep the flasks in the lab.

In the first category, you will find most bases, with a notable exception: ammonia.

In the second category, are most acids + ammonia NH3
HCl, NH3 because they are gases;
HNO3, H2SO4, because they are liquid

Answer 8

Okay..