Textbook Problem J.1 Part C

[vuongnaomi1L]

This question asks to classify whether certain molecules are acids or bases. For part C, since KOH has an H, I thought this means that it could give off a proton and be an acid. Why is KOH a base and not an acid?

[Sreeram Kurada 3H]

KOH is a strong base since it has OH.

[jessicaosuna_1F]

Hi! So here you're looking at the OH which has a negative charge, OH-. This is a component of bases. You know its a strong base because strong bases tend to be hydroxides (OH-'s) bound to molecules from the first and second columns of the periodic table.

[Katherine_Douglas_1F]

An easy way to avoid making this mistake in the future is focusing on the components of the molecule. If there is an O and an H right next to each other (usually at the end of a molecule) it is almost certainly a base. Also, molecules with N are often bases. In a similar fashion, molecules with an isolated H (often at the beginning of the molecule) is almost always an acid. Same with those molecules that end in -COOH. These are just the general rules/themes, however, so make sure to look closely and find any exceptions.