How to Dissolve Limestone

Limestone outcroppings such as these are constantly dissolved, bit by bit, through the action of mildly acidic rain.

If you've ever seen pictures of stalactites and stalagmites in a cave, you've seen one of the effects of dissolving limestone. Over time, the steady dripping of dissolved limestone produces these beautiful cave formations. In nature, limestone is generally dissolved by a very mild acid known as carbolic acid. Fortunately, carbolic acid is very easy for the average homeowner to acquire.

Things You'll Need

• Limestone
• Glass bowl
• Clear soda pop

Instructions

1. Place a piece of limestone (or seashell) in a glass bowl.

2. Fill the glass bowl with a clear carbonated beverage, such as 7-Up or ginger ale.

3. Observe the limestone over the next hour or so, watching especially for the release of tiny bubbles. Bubbles indicate that the limestone is dissolving and releasing its stored carbon dioxide gas.

Tips & Warnings

• Limestone dissolves much more rapidly under the effect of a stronger acid, such as hydrochloric acid, but you must take care if using such strong acids.

References

• National Park Service: Make a Cave
• Experts 123: What Are Somer Easily Obtainable Items I Can Use to Dissolve Limestone
• Geology.com: Limestone