Equivalent and the law of equivalents
Answers are for parents and teachers.
1
Find the equivalent mass of Mg(OH)₂ (M = 58 g/mol).
29
2
2.7 g of aluminium combines with 2.4 g of oxygen. Find the equivalent mass of aluminium.
9
3
5.6 g of KOH (E = 56) was used to neutralise 3.65 g of an unknown monobasic acid. Find the equivalent mass of the acid and identify it.
E = 3.65·56/5.6 = 36.5 — hydrochloric acid HCl.
4
Find the equivalent mass of iron in FeO (Fe is divalent, A = 56).
28
5
Is the equivalent mass of an element a constant value? Explain with an example.
No, it depends on the valence: for sulfur it is 8 in SO₂ and ≈ 5.33 in SO₃.