pH Indicators from your Garden

Summer is a great time to be outside enjoying the sunshine. When you're outside to stop and smell the roses, don't forget to pick some petals to bring inside for some chemistry fun. You can puree the petals in a blender with a little water, filter the solids using a coffee filter, and use the liquid as a pH indicator. The oxonium salt of the cyanin pigment in the petals (not white roses) turns from red to blue in a basic solution. You can use your rose pH indicator like any other pH indicator solution, just be sure to refrigerate any unused indicator. Many other common garden plants can be used the same way, as well as several common household chemicals. Let's play with pH...