Cl- and F-

[Meachelle_Lum_1I]

Why is it that Cl- does nothing when dissolved in water but F- has the potential to gain a proton and become HF?

[Andre_Galenchik_2L]

As HCl is a strong acid, it will stay dissociated as H+ and Cl- (an acid is stronger the more likely it dissociates and releases a H+). On the other hand, as HF is a weak acid, it will more likely go back into HF as it does not like to be in its dissociated form of H+ and F-.

[Gabriela Aguilar 4H]

HCL when disassociated it does so completely which makes it a strong acid because it won't go back with the H+ and therefore is able to donate the proton. On the other hand, HF will disassociate but not completely and therefore will go back with H+ making a weak acid because it is harder to take away the proton from it.

[Joaquin Andrade]

Since HCL is a strong acid, it will stay dissociated in water. This is also true for HBr and HI.

[Claudia Luong 4K]

Strong acids completely dissociate. HCl would completely dissociate into H+ and Cl- ions and therefore won't be able to turn back into HCl while HF is a weaker acid, so it doesn't completely dissociate. Since HF doesn't completely dissociate, F- has the ability to pick up a proton/hydrogen and become HF