Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

Which type of rock is particularly susceptible to weathering by acid?

1. Granite

2. Limestone

3. Sandstone

4. Igneous

The correct answer is: Limestone

Limestone is particularly susceptible to weathering by acid due to its composition and the mineral calcite, which is primarily made up of calcium carbonate. When acid, such as carbonic acid formed from rainwater, comes into contact with limestone, a chemical reaction occurs. This reaction leads to the dissolution of calcite, resulting in the wearing away of the rock. This process is a key factor in the formation of karst landscapes, characterized by features like caves and sinkholes, which develop as limestone is gradually eroded away by acidic waters. In contrast, granite, sandstone, and igneous rocks generally contain minerals that are more resistant to acid weathering, making them less susceptible to such processes. This inherent difference in mineral composition and chemical reactions is what underlies limestone's unique vulnerability to acid weathering.