Final answer:
Limestone, containing calcium carbonate, is the rock type most susceptible to dissolution processes due to its slight solubility in water and the chemical reactions that occur when it's exposed to acidic conditions, such as acid rain.
Step-by-step explanation:
The rock type that would be most susceptible to dissolution processes given the same water properties and rock thickness would be limestone. Limestone often contains calcium carbonate, which is slightly soluble in water, especially when the water is slightly acidic. When acid rain falls, it dissolves the calcium carbonate in limestone over time, through a series of chemical reactions leading to the formation of soluble ions. This dissolved limestone can then be carried away by groundwater or streams, carving out landforms like caves or even the Grand Canyon over geological time scales. For example, the dissolution of limestone can lead to formations like stalactites and stalagmites in caves, as the dissolved calcium carbonate re-precipitates when the water loses carbon dioxide.
Solubility can be influenced by various factors, including the strength of the electrostatic forces between the ions in the rock and the hydration energy from the water molecules. If a rock is composed of minerals that have strong electrostatic forces that are not easily overcome by the solvation forces of water, such as calcium carbonate, it will dissolve more slowly. Conversely, rocks containing highly soluble minerals, like halite (rock salt), would dissolve more quickly when exposed to water.