Question

Due to mechanical weathering, a small boulder has broken into several pieces. Explain how this will affect the rate at which the boulder weather chemically.

Answer 1

Answer:

It will increase the rate of chemical weathering.

Explanation:

Weathering is the breaking down or dissolving of rocks and minerals on the surface of the earth into smaller grains or soil.

Weathering can occur either by biological, chemical or mechanical means.

When mechanical (or physical) weathering breaks a small boulder into pieces, this will lead to an increase in the rate of chemical weathering.

Chemical weathering involves chemical reactions or changes that occur in rocks which results in changes in their size and composition. This chemical reactions that breaks down rocks include hydrolysis by water and oxidation by oxygen. The rate of chemical reactions increase with increase in surface area of the substances reacting.

When the boulder is broken into smaller pieces, it exposes a larger area of these rocks to the chemical reactions that weather rocks. For example, a larger surface of the rock may be exposed to water result in faster reaction of the rock salts with water, and thus, the rock particles are broken down faster.