RPAL Study Guide 2026
Everything you need to pass the RPAL exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 RPAL Exam Format at a Glance
📚 RPAL Topics to Study (22)
✍️ Sample RPAL Questions & Answers
1. In the reaction 2H₂ + O₂ → 2H₂O, if you have 4 mol H₂ and 1 mol O₂, which is the limiting reagent?
The reaction requires 2:1 ratio of H₂ to O₂, so 4 mol H₂ needs 2 mol O₂, but only 1 mol O₂ is available, making O₂ the limiting reagent.
2. After the reaction in the sandwich analogy (10 bread, 4 cheese, 2 bread + 1 cheese per sandwich), how many bread slices are left over?
4 sandwiches require 8 bread slices; 10 − 8 = 2 slices of bread remain as leftover.
3. For N₂ + 3H₂ → 2NH₃, what is the mole ratio of H₂ to NH₃?
The coefficients are 3 for H₂ and 2 for NH₃, giving a 3:2 mole ratio.
4. In an RPAL table, the 'leftover' row reports which value?
The leftover row in an RPAL table shows the unreacted amount of each substance after the reaction has gone to completion.
5. A recipe analogy for limiting reagent: if making sandwiches requires 2 slices of bread and 1 slice of cheese, and you have 10 bread and 4 cheese, what is the 'limiting reagent'?
10 bread can make 5 sandwiches, but only 4 cheese are available, limiting production to 4 sandwiches — cheese is the limiting ingredient.
6. Which of the following best describes what happens to atoms during a chemical reaction?
In chemical reactions, atoms are rearranged — bonds are broken and formed — but atoms themselves are neither created nor destroyed.