Many years ago engineers built a canal to control water flow along a river. at the time of building the canal, the engineers did not know that they used a rock that contained iron particles. over time, the rocks have been exposed to a constant supply of water which has given the rocks an orange-brown color. it has formed a new compound called limonite. what type of weathering has occurred to these rocks?

Chemical weathering due to Oxidation occurs to these rocks.

Explanation:

The process of Chemical weathering results in changing the rocks composition resulting in the transformation of rocks because water reacts with minerals present in the rocks thereby creating various chemical reactions. It is a gradual and a continuous process because the minerals present in the rock changes according to the environment. Oxidation and hydrolysis process plays a major role in Chemical weathering.

The oxidation of (iron) and combination with oxygen and water  usually occurs and this results in the formation of hydroxides and oxides such as goethite, limonite, and hematite. This results in giving a orange -brown colors to the rocks and makes it weak. It can also be termed as 'rusting'.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-