861 past contests
Topic 9 · Balancing and applying the softening reaction of temporary hardness with slaked lime
Topic 33 · Balancing the roasting equation of antimony sulfide (stibnite)
Topic 14 · Balancing the equation for tellurium(iv) oxide reacting with hydrogen iodide
Topic 14 · Balancing the equation for arsenic dissolving in fused sodium hydroxide
Topic 30 · Three postulates of dalton's atomic theory
Topic 21 · Reforming to raise octane number via branching, alkenes and aromatics
Topic 21 · Catalytic cracking of long-chain hydrocarbons to smaller molecules
Topic 21 · The octane rating scale and its n-heptane/iso-octane reference compounds
Topic 1 · Riddle: concentrated sulfuric acid, the most manufactured chemical
Topic 34 · Only iodide, not chloride or bromide, gives a yellow precipitate with pb2+ (true/false)
Topic 34 · A cream precipitate with agno3 indicates a bromide halide (true/false)
Topic 34 · A reddish-brown vapor with conc. h2so4 suggests a nitrate is present, not any generic solid (true/false)
Topic 31 · True or false: chemical symbols of antimony, germanium and tungsten
Topic 7 · Mole ratio of sulfur to sulfuric acid when sulfur is oxidized by hot concentrated h2so4
Topic 7 · Moles of dilute nitric acid reacting with copper (per the balanced equation producing no)
Topic 34 · Moles of h2s gas from hydrolysis of aluminium sulfide
Topic 39 · Volume of oxygen at stp discharged at the anode from a given charge
Topic 39 · Mass of copper discharged at the cathode from a given charge
Topic 38 · Moles of hydrogen gas discharged at the cathode from a given charge (faraday's law)
Topic 22 · Carboxylic acid + ammonia salt formation