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Questions 2.2(c)

  1. Describe what is observed when
    1. Steam is passed over heated magnesium ribbon.
    2. The solid product is mixed with water, shaken and tested with litmus.
  2. Write a chemical equation for the reaction between
    1. magnesium and steam
    2. calcium and steam
    3. the product in 1(a) and water
  3. Suggest a reason why Group II elements are referred to as alkali earth metals.


Answers to Questions 2.2(c)

    1. Magnesium burns with a bright white flame (light) to form a white powder and a gas that extinguishes a burning splint with a pop sound.
    2. The powder slightly dissolves in water to form a solution that turns red litmus blue; that is an alkaline solution (Much of the powder remains undissolved).

  2. (a) Mg   +   H2O   ⟶  MgO   +   H2
    (b) Ca   +   H2O   ⟶  MgO   +   H2
    (c) MgO   +   H2O   ⟶  Mg(OH)2
  3. Their hydroxides dissolve (though only slightly) in water to form alkaline solutions.