[header] How to test the acidity of your rain [title] Gather the necessary materials. [step] For this experiment, you will need to collect some rain water and get some strips of ph paper. Ph paper is a special type of paper that changes color based on how acidic or basic a solution is. 
The paper comes with a separate color chart that allows you to identify the ph according to the color. [substeps] Ph paper can be purchased at gardening or pool stores.