The law of equivalents
Answers are for parents and teachers.
1
Equivalent mass of Mg(OH)₂ (M = 58, 2 OH groups).
29 g/mol
2
23 g of sodium combine with 8 g of oxygen. Find E(Na).
23 g/mol
3
How many grams of NaOH neutralize 98 g H₂SO₄ (E = 49 and 40)?
80 g
4
How many grams of hydrogen does 18 g of aluminium (E = 9) displace from an acid? (calculation only; the experiment is not done)
2 g
5
Why are the molar mass and the equivalent mass not always equal?
The equivalent mass is the molar mass divided by the valency (or the number of H/OH); they are equal only when this number is 1.