Question

Is there any evidence that would support the notion that the same material in a powder form would react fast than in a lump form?

Answer 1

The same material in powder form reacts faster than in a lump because the powdered form of material has greater surface area than the lump. The rate of reaction depends upon the surface area, Greater the surface area faster will be the reaction.

We can have examples in support of this

1.powdered calcium carbonate reacts with hydrochloric acid at much faster rate than the calcium carbonate in form of lump or marble.

2. During catalytic decomposition of hydrogen peroxide, oxygen is evolved with faster rate if the catalyst manganese (IV) oxide is in powdered form.

The simple reason if instead of lump if the material is in powdered form the chances of collision increases and hence rate of reaction increases.