pH strips are all over the place these days. You can buy them pre-made, or you can make your own. But how do they actually work? They measure the pH of a solution, which is a measure of acidity. The pH scale is a logarithmic scale, with 0 being the end point. The lower the pH number, the more acidic something is. A pH of 0 is considered completely neutral. So, what is pH? Well, it measures the amount of hydrogen ions in a solution. In general, hydrogen is the most electronegative element, and it likes to be in the state that is most electronegative. Of course, not all water molecules are the same, so not all hydrogen
They’re cheap, and have a proven track record of accurately detecting pH levels, so it’s easy to see why pH strips are so popular among hobbyists and DIY-ers. But how do they work? pH strips rely on hydronium ion (H+) ions to create a chemical reaction, and their chemical reaction depends on the pH level of the solution. This pH level is measured by the strip as pH drop, which is the amount of H+ ions remaining after the chemical reaction. As the pH drops, so does the concentration of H+ ions, until the solution is no longer acidic.
pH strips are used to test the acidity of a solution or chemical in a laboratory. They consist of a strip of paper soaked in a colored indicator solution which changes colors in response to the presence of acid or alkali.
Cabbage is no longer just for coleslaw! Learn about pH strips and how to make your own in the comfort of your own home.
pH strips are pieces of paper that change color based on a liquid’s pH (acidity or alkalinity). pH strips are a low-cost, high-accuracy method of determining the pH of any liquid, in this case urine. pH strips are made by soaking a strip of filter paper in various Indicators of pH (more on that later) and allowing it to dry. The majority of pH strips are made to test urine, water, and saliva.
pH strips come in a range of shapes and sizes. They differ in terms of sensitivity and the pH range for which they were built. The pH strip’s working range is smaller the more sensitive it is.
Why is there a restriction? You can only distinguish so many colors, after all. It can be tough to tell whether your strip is bluish-green or greenish-blue.
You modify your indicators now, based on the pH range you want and how sensitive you need the strip to be. So you can have a pH strip with a range of 1-14, but it won’t be very sensitive; or you can have a pH strip with a range of 5.5-8.5, but it won’t be as sensitive.
The second question is: how do you determine what pH level is bluish-green? The pH strips are dipped into solutions with different known pHs to create a color legend (i.e., to find out what color belongs with what pH). If you dip your pH strip into a solution with a pH of 5 and it turns dark blue, you know it’s a pH of 5, and so on until you’ve covered the entire range of the strips. You don’t have to do this; it’s likely that someone else has already done it for you; the color legend will be supplied in the strip package.
pH Indicators
pH indicators are typically weak acids or bases that change color when exposed to specific pH levels. Methyl red, for example, is a typical indicator that becomes red at pH 5 and yellow at pH 6.
Graph of pH indicators
Mini-lecture on Chemistry
What causes them to change color? I’ll give you a quick rundown of the theory. Acids and bases are defined in a variety of ways, but the simplest approach to grasp them is to think of them as compounds that exchange a proton. The proton in this situation comes from a hydrogen ion, which is a positively charged hydrogen that gives us the “H” in “pH.” Acids are substances that donate a proton, while bases are molecules that take one away (aka alkaline). As a result, the hydrogen donor is acid, while the hydrogen receiver is basic.
When an acid or base takes or donates a proton, the color changes. When this happens is determined by the chemical’s unique properties. Some indications are more complicated, with many color changes. For an indicator with several modifications, see the following experiment: From red to blue, then blue to yellow, and finally yellow to red.
Fortunately, there is a large selection of pH indicators that alter at a variety of pHs and in a variety of colors, allowing for the creation of customized pH strips.
Experiment at Home
You can make your own pH strip with a red cabbage, boiling water, and a McGyver wig if you’re interested (optional).
To begin, puree your red cabbage in a blender with 2 cups hot water (and you thought your blender was exclusively for shakes!). Using a fine mesh strainer, drain the bits and preserve the liquid. (The leftovers can be used to create cabbage soup.) The liquid (or cabbage tea, as the case may be) is your pH indicator.
Get a coffee filter, cut it into strips, and soak the strips for a few hours in the cabbage tea – I mean pH indicator. Remove the strips and set them aside to dry. Make sure you don’t spill any because it will stain. That’s it! pH strips made just for you!
To begin with, your pH strips will most likely be violet-bluish (pH 7). (see below). Dip your strips in vinegar, lemon juice, cola, baking soda solution, antacids, or bleach (carefully) and observe how the color changes. The list goes on and on – albeit you might not notice much of a difference with some of them. For the greatest results, use a different strip each time. Have a blast!
The color gradient of the cabbage indicate
| pH | 2 | 4 | 6 | 8 | 10 | 12 |
| Colour | Red-orangish | Purplish | Violet | Blue | Blue-green | Yellowish green |
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pH strips are little gadgets that you stick to your tongue and then put in your mouth to analyze how acidic or alkaline you are. There are many different kinds of pH strips and all of them have different functions. This post will talk about the pH strips I own and the things they can tell you.. Read more about ph indicator strips and let us know what you think.
Frequently Asked Questions
How does a pH test strip work?
A pH test strip is a strip of paper that changes color in response to the pH level of a solution. The color change can be seen with the naked eye, and it is typically measured in either red or blue.
How does a pH indicator work?
A pH indicator is a chemical solution that changes color depending on the acidity or alkalinity of its environment.
How do you test pH levels with strips?
There are a few ways to test pH levels with strips. One way is to use litmus paper, which will change color depending on the pH level of the solution. Another way is to use a digital meter that can measure the pH level of a solution.
