Question

2. The following table gives the atomic numbers of elements V, W, X, Y and Z.
Element: V, W, X, Y, Z | Atomic number: 11, 16, 18, 19, 24
(a) Which of the elements: (i) belong(s) to group 1? (ii) is/are noble gas(es)? (iii) form(s) coloured compound(s)? (iv) form(s) an anion? (v) react(s) with water to liberate hydrogen? (vi) react(s) with water to form alkaline solution?

Accepted Answer

(i) V & Y belong to group 1 (11V=2,8,1), (19Y=2,8,8,1).
(ii) X is a noble gas (18X=2,8,8).
(iii) Z forms coloured compounds (since it is a transition element).
(iv) W forms an anion.
(v) V and Y react with water to liberate hydrogen.
(vi) V and Y react with water to form alkaline solution (V is sodium, Y is potassium): 2Na(s)+2H2O(l)→2NaOH(aq)+H2(g); 2K(s)+2H2O(l)→2KOH(aq)+H2(g).

WAEC Chemistry 2011 Theory — Question 8

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