By John Brennan, Updated Aug 30, 2022
When you’re starting out in chemistry, a solid grasp of the solubility rules is essential. Rather than rote memorization, these rules help you predict which ionic compounds will dissolve in water and which will form a precipitate. Below are proven techniques to internalize them quickly and reliably.
A mnemonic can turn a long list of exceptions into a memorable phrase. One popular example is:
“Not All Attractive Fun Cheerleaders Buy Indecent Skirts.” Each initial corresponds to a soluble class: Nitrates, Acetates, Ammonium, Fluorides, Clorides, Bromides, Iodides, and Sulfates. Remember that several of these families have notable exceptions, so you’ll need to memorize or create a separate mnemonic for those outliers. For instance, chlorides are soluble except when paired with mercury (Hg), silver (Ag), or lead (Pb). A quick “HAP” reminder can help you recall the problematic ones.
Solubility often follows the periodic table’s groups. Anything containing a group 1 element (alkali metals) is soluble. Likewise, group 17 halides are generally soluble, with the same exceptions for Hg, Ag, and Pb. Fluorides are an exception when combined with group 2 metals such as strontium (Sr) or barium (Ba). Since a periodic table is always on hand during exams, aligning your knowledge with elemental positions can save you time and reduce errors.
For many students, singing the rules to a familiar tune makes them stick. A simple verse that can be set to the melody of “99 Bottles” is available in the Resources section. Even if you can’t sing aloud during a test, silently humming the rhyme can reinforce the sequence in your mind.
Write the rules, or a concise list of soluble compounds and their exceptions, repeatedly. Consistent ordering helps solidify the information and keeps it organized mentally. Practice until you can recite the list without a reference.
Mercury, lead, and silver halides are the most common outliers. Spotting one of these on a multiple‑choice question immediately eliminates it from consideration, narrowing your options and boosting accuracy.
With these strategies, you’ll move beyond memorization to genuine understanding—allowing you to confidently tackle any solubility‑related question on the exam.
