861 past contests
Topic 25 · Elimination reactions that form alkenes: dehydration, dehydrohalogenation and reduction
Topic 31 · Naming an element from its two-letter symbol's first letter
Topic 14 · Bonding character and brittleness of metalloids (true/false)
Topic 14 · Riddle: iron, the most abundant element on earth by mass
Topic 6 · Solubility product: concentration from ksp, common-ion suppressed solubility, and ionic product after mixing
Topic 5 · Molar mass of a branched alkane from its systematic name
Topic 7 · Oxidation states of chromium and carbon in given compounds (true/false)
Topic 11 · Mass of a metal that reacts completely with a given gas volume at stp
Topic 5 · Identifying a possible functional group family from a molecular formula alone
Topic 28 · Identifying an element from its electron configuration
Topic 28 · Reactivity trends: electron count vs electron configuration (true/false)
Topic 7 · Oxidation state of manganese in permanganate and its reduction products by medium (true/false)
Topic 14 · Riddle: cobalt
Topic 20 · Concentration of a solution is unchanged by taking a smaller sample volume
Topic 1 · Molar mass of a hydrated complex salt
Topic 6 · Predicting the solubility of an ionic product from solubility rules
Topic 23 · Systematic name
Topic 14 · Riddle: calcium carbonate, an insoluble salt reactive with acids
Topic 5 · Cyclopropane: the simplest cycloalkane and its angular strain (true/false)
Topic 30 · What dalton's atomic theory did and did not claim (true/false)