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Properties of Acids

Defines what an acid is and discusses their common characteristics.

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Practice Properties of Acids
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Are your beauty products acidic or basic?

What are the pH levels of your beauty products?

Credit: the Italian voice
Source: http://www.flickr.com/photos/77476789@N00/2254327579/in/photolist-4rd23T-byceD5-wPJ5P-2aVLAJ-8Hy1Wr-8T2va2-h5p4S-6vPPX8-9QqWdB-8BNEry-5JnqPy-5JiaCe-5dzPZ5-rx1uq-bLrE7M-8ru6Pu-KRGvu-cfFUX3-97hbeP-8anjmN-7gUy1C-ippiP-24HtNE-75g2u1-4hKcem-qqdQL-5WrDHC-59d3Nd-JcUFt-amvAsa-AMXrT-6YARBV-auCz3B-TauuL-4ZsQND-7BvfXk-8HxGGe-6YARze-hGu6S-3jUJtm-7uMUgo-7vAuMg-2fDEYy-3jUJvU-AMXrS-2fDF5U-d2zjGU-bu7Xmr-edxwz1-7Q2hAh-3dLjcV
License: CC BY-NC 3.0


When you put a product on your hair or body, you don't want it to be too acidic or basic. Either way, it could be extremely uncomfortable! In chemistry, pH measures the concentration of hydrogen ions. The pH scale is numbered from 0 to 14. If a substance’s pH is less than 7, it is an acid. If the pH measure is 7 it’s neutral. If it’s higher than 7, it’s a base. One common example of a base is soap.

  1. What does soap feel like?
  2. What does soap taste like when it accidentally gets into your mouth?
  3. Based off of what you have just determined, what do you think are some other examples of bases?  Based on these examples, what might be some properties of bases?
  4. What is a test you can do to determine whether something is a base or an acid?  
Lets investigate another beauty product. One thing that most people use is shampoo. Initially, we might expect shampoo to behave much like soap. It turns out grocery store brands have a pH average of 5.96! 
  1. Is grocery store brand shampoo a base or an acid?
  2. Our hair is actually slightly acidic and has a pH between 4.5 and 5.5.  How does the pH of shampoo affect    your hair?
  3. What do you think the perfect pH for your shampoo is?



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