weak acids and bases

[906430805]

Anyone have any tips on identifying weak acids and bases?

should we be relying on identifying them through their molecular structure (eg. lone pairs, formal charges etc)?

[Kaia Hitzeman 2E]

Hi 906430805,

I think we just need to have the strong acids and strong bases memorized (ie. strong acids: BICC PEN), and anything else that does not fall into one of those categories is considered a weak acid or weak base. Typically, strong acid formulas tend to start with H and weak base formulas tend to contain N. Many times it is fairly straightforward to determine if an acid or base is strong/weak based on its molecular formula, however, if you are given a Lewis structure, it would be best to write out the molecular formula and analyze it from there. Some indicators of whether a substance is an acid or base are usually if a substance has a negative charge it is typically a Lewis base, and if it is a positive charge it is a Lewis acid-- but this also depends on the reaction!!! Once you determine whether a substance is an acid or base, based on your memorized strong acids and bases, determine if it is strong/weak.

Hope this helps!
Kaia H

[706381863 Yuxuan Ren]

I don't think we can identify them from a molecular perspective, at least not for now. But we can memorize the 7 strong acids as BICC PeNS, which means Hydrobromic acid, hydroiodic acid , hydrochloric acid, chloric acid, perchloric acid, nitric acid and sulfuric acid. For the strong bases we also need to memorize the most common ones, such as the hrdroxides of alkali and alkali earth metals or period 3 transition metals.We can also learn from their dissociation in water, since strong acid and bases all dissociate fully in water while their weaker counterparts only dissociate partially.