Friday, March 15, 2013

pH Baseline Reference -Cabbage Indicator

Although doing a pH lab seated at a table is hands-on, and might be considered "fun" (depending on the mood) we know it can help make the spectrum of pH more understandable. But don't be fooled; it isn't doing science, its learning science. Once students understand a bit about the pH spectrum, they should be encouraged to design an experiment to test the pH of substances for a real reason! Whether you use cabbage indicator solution, DIY pH papers, or store bought pH papers, it is a lot of fun to see how substances in the environment vary in their pH.

Using pH papers as data collection to DO real SCIENCE!:
We decided to test area snowfall from different areas of our yard. We selected samples from snow piles under a tree, near our shed, and a water sample from a large puddle in our front yard.  

Boy collecting snow sample in order to test pH:

We used a paper plate, divided into 4 quadrants and labeled A-D. The clipboard held the paper that we wrote down where the samples came from, and also held our paper plate in place (sort of....we're in the country, and its windy) so we could scoop snow or water samples using our plastic spoon.

 Boy collecting snow sample to test pH as a STEM lab:

Boy collecting water sample to test pH in a STEM lab:

Once we came inside, we used our DIY pH paper strips, to test our water/snow samples to see if their pH was different at all. We compared our pH papers to the pH baseline scale that we constructed on a previous day (free download at the end of this post) that showed the color variance of the full pH spectrum. 

Boy using pH paper to test snow samples in a STEM lab:

I printed the baseline pH table on card stock and laminated it so the wet pH paper strips could be placed right on them for direct comparison.

Use a basline pH scale from to do on-the-field pH testing

For our field science experiment, we found that all the snow and water samples were in the "normal" or "7" range. However, I have a feeling we will be packing our pH paper strips in our hiking bag this spring and summer for more STEM fun.  For the FREE download, visit my Teachers Pay Teachers Store.

This is a baseline pH scale students can make using cabbage as a pH indicator: They fill in the "color" row with crayons, and use this as their basline reference for all future pH test they make. Free download available via


If you liked this lab be sure to visit my other posts on pH:

Using Cabbage Juice to make pH indicator solution
DIY pH Paper using Cabbage Juice and Coffee Filters

Keywords: free download, homeschool lab, on the go science, STEM lab, pH, free download, chemistry, field science, inquiry,

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