Use 3 free Unit 07 practice problems to get started. When you want more reps on moles, molar mass, percent composition, and formulas, premium unlocks Quick Sets of 3, Standard Sets of 9, and Extended Sets of 18 from this 81-problem bank.
3 Free Sample Problems
Work these 3 to find out whether the mole conversion path is clear enough to follow on your own — before the setup isn't right in front of you anymore.
#4Mole Conversion
How many grams are in 3.50 mol of calcium carbonate (CaCO3)? (Molar mass = 100.09 g/mol)
#5Avogadro's Number
What does Avogadro's number (6.022 × 1023) represent?
#6Empirical Formula
A compound contains 40.0% C, 6.7% H, and 53.3% O by mass. What is its empirical formula? (Atomic masses: C = 12.01, H = 1.008, O = 16.00)
Prep for the test — not just the homework
The 3 free problems show you where you stand. The full bank is how you close the gaps before the test.
Randomized every time — fresh problems that force real understanding, not answer memorization
Full worked solutions — see exactly where your setup went off track, not just whether you were right
81 problems across grams-to-moles conversions, molar mass, particles, and empirical formulas
Quick (3), Standard (9), or Extended (18) — use whatever fits your schedule
Filter by type — focus on calculation, concept, or multi-step problems first