861 past contests
Topic 19 · Percentage composition by mass in a compound
Topic 7 · Oxidation state determination across two compounds
Topic 1 · Predicting the products of a double displacement (metathesis) reaction
Topic 22 · Systematic (iupac) name of an ester from its parent acid and alcohol
Topic 29 · Effect of atomic radius, nuclear charge and shielding on first ionization energy
Topic 25 · Major product of alkane monochlorination via the most stable (tertiary) radical intermediate
Topic 25 · Addition vs substitution reactions of alkenes and alkanes with halogens (true/false)
Topic 3 · Identifying salts as neutral or acidic from their parent acid and base (true/false)
Topic 16 · Riddle: filtration, a solid-liquid/gas separation technique
Topic 2 · Heat released from the enthalpy of solution and mass of a dissolved salt
Topic 1 · Mass of aluminum produced from aluminum oxide and carbon (thermite-type reaction)
Topic 31 · Elements with atomic number above 10 whose symbol starts with h
Topic 19 · Empirical formula from percentage composition
Topic 6 · Equilibrium constant kc with correct units from equilibrium concentrations
Topic 27 · Components of a mass spectrometer: ionization chamber, mass analyzer and detector
Topic 19 · Molecular formula from a compound's mass and moles, given its empirical formula
Topic 32 · Classifying elements as main group metal, transition metal, metalloid or transuranium
Topic 14 · Riddle: nickel
Topic 2 · Bonding and hybridization in graphite, silicon dioxide and graphene (true/false)
Topic 21 · Composition of crude petroleum and natural gas, and fractional distillation (true/false)