861 past contests
Topic 5 · Systematic name of a carbonyl compound from its molecular formula
Topic 28 · Identifying a valid set of quantum numbers (n, l, ml, ms) for an electron in a given orbital or subshell
Topic 7 · Average oxidation state of sulfur in sodium thiosulfate (na2s2o3)
Topic 19 · Molecular formula from percent composition and a given molar mass
Topic 6 · Solubility product: concentration from ksp, common-ion suppressed solubility, and ionic product after mixing
Topic 14 · Identifying reagents used in standard chemical tests (water detection, unsaturation)
Topic 3 · Minimum volume of water needed to dilute an acidic product to a target ph
Topic 9 · Mass of product formed from a redox equation balanced by oxidation-state electron transfer
Topic 1 · Mass of sulfur dioxide released from the sulfur content of a fuel burned
Topic 11 · Molar mass of a gas from its rate of effusion relative to a known gas (graham's law)
Topic 11 · Volume of an ideal gas from moles, temperature and pressure (pv = nrt)
Topic 12 · Concentration of a carbonate/bicarbonate solution from titration, using the indicator to find the reacting mole ratio
Topic 2 · Special hydrogen bonding in ethanoic acid (dimer formation) and properties of water arising from hydrogen bonding
Topic 2 · When hydrogen bonding does and doesn't occur (true/false)
Topic 2 · Comparing the stability of two structural isomers via combustion enthalpies from bond energies
Topic 2 · Vsepr shapes of covalent fluorides from central-atom electron domains (linear, bent, planar, pyramidal)
Topic 14 · Systematic (iupac) name of a polyatomic oxoanion
Topic 2 · Standard enthalpy of formation of a hydrocarbon from combustion and formation data (hess's law)