Chemistry Trivia Questions and Answers

25 questions on Chemistry, each with the answer and a short explanation. Part of the Science set in Rapid Fire Trivia, which holds 2,000 questions across 5 topics.

All 25 questions, with answers

1. 1What property describes how readily a liquid changes into vapor?

   AnswerVolatility

   Highly volatile liquids have comparatively high vapor pressures and evaporate readily under ordinary conditions.

2. 2Which element is added to table salt to help prevent thyroid deficiency?

   AnswerIodine

   Iodized salt supplies iodine needed for thyroid hormones that regulate metabolism and development.

3. 3Which conditions are normally required for iron to rust readily?

   AnswerOxygen and water

   Rusting is an electrochemical corrosion process that needs oxygen and moisture around the iron surface.

4. 4What color does turmeric indicator become in a basic solution?

   AnswerReddish-brown

   Curcumin in turmeric changes structure in alkaline conditions, producing a reddish-brown color.

5. 5Washing soda is the common name for which compound?

   AnswerSodium carbonate

   Washing soda is hydrated sodium carbonate, an alkaline compound used for cleaning and water softening.

6. 6Which gas is released when hydrogen peroxide decomposes in the presence of a catalyst?

   AnswerOxygen

   Hydrogen peroxide breaks down into water and oxygen, a reaction often accelerated by catalysts.

7. 7Dry ice is the solid form of which substance?

   AnswerCarbon dioxide

   Solid carbon dioxide changes directly into gas at ordinary pressure instead of forming a liquid puddle.

8. 8What element is the lightest in the periodic table?

   AnswerHydrogen

   Hydrogen has one proton and usually one electron, giving it the smallest atomic mass.

9. 9The symbol O belongs to which element?

   AnswerOxygen

   Oxygen uses the symbol O and supports aerobic respiration in most complex organisms.

10. 10What laboratory glassware is designed mainly for measuring liquid volume accurately?

    AnswerGraduated cylinder

    Marked graduations allow a cylinder to measure volume more accurately than ordinary beakers.

11. 11Among these metals, which is strongly attracted to an ordinary magnet?

    AnswerIron

    Iron is ferromagnetic, allowing its magnetic domains to align strongly with an applied field.

12. 12Which metal is liquid at ordinary room temperature?

    AnswerMercury

    Mercury’s unusual metallic bonding gives it a melting point below typical room temperature.

13. 13Rubbing alcohol commonly contains which alcohol?

    AnswerIsopropanol

    Isopropanol evaporates readily and dissolves many oils, making it useful for cleaning and disinfection.

14. 14Which lightweight metal is widely used for beverage cans?

    AnswerAluminium

    Aluminium is light, formable, recyclable, and protected by a thin oxide coating.

15. 15Quartz and ordinary silica glass are built mainly from which compound?

    AnswerSilicon dioxide

    Silicon dioxide forms networks of silicon and oxygen atoms in quartz and many glasses.

16. 16Which gas causes bread dough to rise as yeast ferments sugar?

    AnswerCarbon dioxide

    Yeast releases carbon dioxide, and trapped bubbles expand the dough before and during baking.

17. 17Why can soap help wash greasy material away with water?

    AnswerSoap molecules interact with both oil and water

    Soap’s hydrophobic ends enter grease while hydrophilic ends face water, forming washable droplets called micelles.

18. 18Which household product commonly contains sodium hypochlorite?

    AnswerChlorine bleach

    Sodium hypochlorite is an oxidizing disinfectant that also removes many colored stains.

19. 19In salt water, which substance acts as the solvent?

    AnswerWater

    The solvent is the component that dissolves the solute and is usually present in greater amount.

20. 20Hard water commonly contains relatively high amounts of which dissolved ions?

    AnswerCalcium and magnesium ions

    Dissolved calcium and magnesium can form scale and reduce soap’s ability to produce lather.

21. 21What element commonly produces a bright yellow flame in a flame test?

    AnswerSodium

    Excited sodium atoms emit intense yellow light near 589 nanometres during electron relaxation.

22. 22Which element is commonly used for incandescent-lamp filaments because of its very high melting point?

    AnswerTungsten

    Tungsten remains solid at extremely high temperatures and can glow brightly without melting quickly.

23. 23Table sugar is chemically known by which name?

    AnswerSucrose

    Sucrose is a disaccharide composed of glucose and fructose units linked together.

24. 24Brass is primarily made from copper mixed with which element?

    AnswerZinc

    Varying the zinc content changes brass color, hardness, and suitability for instruments or fittings.

25. 25What element forms the structural backbone of most organic molecules?

    AnswerCarbon

    Carbon forms four covalent bonds, allowing chains, rings, and complex biological molecules.