Question

(a) Balance the following reactions:

(i) Al + H2SO4 Al2(SO4)3 + H2

(ii) Fe + HCl FeCl3 + H2

(b) Write the limitations of Dobereiner’s classification.​

Answer 1

Answer:

(a)

(i) 2Al + 3H2SO4 → Al2(SO4)3 + 3H2

(ii) 2Fe + 6HCl → 2FeCl3 + 3H2

(b) Limitations of Dobereiner's classification:

Dobereiner could find only three triads; . i.e total of 9 elements only.

However the total number of elements were more than that of those encompassed in Dobereiner's Triad.

Thus, Dobereiner's could not be classify most of the elements known at that time.