Just finished the RPAL Reactants, Products, and Leftovers assessment and wanted to give an honest breakdown of what appeared, since most prep resources are pretty generic.
The exam focuses heavily on stoichiometry and limiting reagent problems. Expect to calculate theoretical yield, actual yield, and percent yield — all three types appeared on mine. The limiting reagent problems ranged from straightforward two-reactant setups to multi-step reactions where you have to identify the bottleneck across a reaction sequence.
Mole calculations were everywhere. You need to be comfortable converting between grams, moles, and molecules without hesitation. If that conversion is slow for you, it eats time on problems that should be quick.
Conservation of mass questions also appeared — not just conceptual but computational. Balancing equations correctly before calculating was non-negotiable. I got one question where an unbalanced equation was given deliberately and you had to recognize and fix it first.
Spent 6 weeks on this. My weakest area coming in was percent yield and it was the most tested concept. Drill that specifically.
This is the most detailed RPAL breakdown I've seen. Bookmarking this for my prep starting next week.
Percent yield being the most tested tracks with what I've heard. The formula is simple but applying it to multi-step reactions throws people off. Good warning.
Mole conversions being slow is literally what tanks most chemistry students. If you can't do those automatically the whole exam becomes a time management nightmare.
The deliberately unbalanced equation question is sneaky. Did you have time to catch it in the moment or did you almost miss it?