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  • Question
  • The main active constituent of tea and coffee is


  • Options
  • A. nicotine
  • B. chlorophyll
  • C. caffeine
  • D. aspirin

  • Correct Answer
  • caffeine 


  • Chemistry problems


    Search Results


    • 1. The metal used to recover copper from a solution of copper sulphate is

    • Options
    • A. Na
    • B. Ag
    • C. Hg
    • D. Fe
    • Discuss
    • 2. The most commonly used bleaching agent is

    • Options
    • A. alcohol
    • B. carbon dioxide
    • C. chlorine
    • D. sodium chlorine
    • Discuss
    • 3. The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in

    • Options
    • A. 1.8 gram of H2O
    • B. 12 moles of KMnO4
    • C. 0.6N H2SO4
    • D. 4.6 gram of C2H5OH
    • Discuss
    • 4. The number of waves made by an electron moving in an orbit having maximum magnetic quantum number is +3

    • Options
    • A. 4
    • B. 5
    • C. 2
    • D. zero
    • Discuss
    • 5. The inherited traits of an organism are controlled by

    • Options
    • A. RNA molecules
    • B. nucleotides
    • C. DNA molecules
    • D. enzymes
    • Discuss
    • 6. The major constituent of air is

    • Options
    • A. nitrogen
    • B. carbon dioxide
    • C. oxygen
    • D. hydrogen
    • Discuss
    • 7. Equal masses of oxygen, hydrogen and methane are kept under identical conditions. The ratio of the volumes of gases will be

    • Options
    • A. 2 : 16 : 2
    • B. 2 : 16 : 1
    • C. 1 : 16 : 2
    • D. 1 : 1 : 1
    • Discuss
    • 8. The first metal used by man was

    • Options
    • A. iron
    • B. copper
    • C. gold
    • D. bronze
    • Discuss
    • 9. The most electronegative element among the following is

    • Options
    • A. sodium
    • B. bromine
    • C. fluorine
    • D. oxygen
    • Discuss
    • 10. The mass of one Avogadro number of helium atom is

    • Options
    • A. 1.00 gram
    • B. 4.00 gram
    • C. 8.00 gram
    • D. 4 x 6.02 x 1023 gram
    • Discuss


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