861 past contests
Topic 25 · Methane and chlorine react under heat/light, not solely in the dark (true/false)
Topic 22 · Ester hydrolysis under acid or base removes the pleasant smell (true/false)
Topic 4 · Natural rainwater carbonic acid can dissolve limestone without human activity (true/false)
Topic 4 · Carbon monoxide does not directly cause acid rain (true/false)
Topic 4 · A well-maintained engine can still emit acid-rain-causing gases (thermal nox) (true/false)
Topic 21 · Alfred bernhard nobel as the inventor of dynamite
Topic 1 · Avogadro's number/constant definition
Topic 14 · Balanced equation for phosphorus(v) oxide reacting with water
Topic 7 · Balanced equation for permanganate reduction by hydrogen peroxide in acid
Topic 33 · Balanced equation for roasting iron pyrites
Topic 21 · Nitroglycerin as the active chemical in dynamite
Topic 29 · Enthalpy of atomization decreasing down group 13
Topic 29 · Atomic size decreasing across period 3 (na to ar)
Topic 29 · Atomic size decreasing across period 2 (li to ne)
Topic 3 · The main factor making chloric acid stronger than chlorous acid
Topic 3 · Comparing the acid strength of chlorous and chloric acid
Topic 29 · Factors beyond shielding affecting first ionization energy
Topic 15 · Rate constant of a first-order reaction from its half-life
Topic 15 · Rate constant of a second-order reaction from its rate and concentration
Topic 2 · H-n-h bond angle in ammonia versus the ideal tetrahedral angle