pH and Acids

  On Monday we began our red cabbage lab. This lab taught us about acids and bases. We used red cabbage juice in our lab because it is a pH indicator. A pH indicator is something that  changes color depending on the pH of the liquid.  On the pH scale 1-4 is an acid 5-7 is neutral and 8-12 is a base. In our lab we had to guess the pH just by the color and then look it up online to see how far off our prediction was based on color. Usually most acids turn pink or purple and most bases turn blue or green. We put 50 mls of lemon soda, apple juice and hand sanitizer into a cup and then poured cabbage juice on top. We made sure to label each cup with a sharpie so we didn't get any mixed up. The apple juice turned red which means it is a weak acid. The hand sanitizer turned purple which means it was a strong acid.

On Tuesday we worked on our lab. We finished shampoo, conditioner, baking soda, and vinegar. We tested the baking soda in varying amounts. The test with  a higher concentration of  baking soda made the color change to more of a green color than the test with the low concentration.

On Wednesday we started a new lab. This lab involved using pH strips and litmus paper to test different liquids for acidity. We tested a vast range of household cleaning products and food items. The majority of the food items were acids and the majority of the cleaning products were bases. To test each liquid if it was a acid or a base we used litmus paper. If the blue paper turned red it was an acid but if it stayed the same it was a base.

On Thursday we finished our lab. One surprising thing I learned in this lab is that most of the food products we eat are very acidic. Acids are very corrosive.

On Friday we attempted to do an elephant tooth paste experiment. We did the elephant tooth paste in science camp and it worked very well. When we attempted to do it to again in class for some reason it didn't work. I think the catalyst in the experiment was just old. A catalyst is something that speeds up a chemical reaction. It worked but it didn't work very well. The substance very slowly pushed to the top. It was not at all like the one we did at science camp. Sometimes it is good when science experiments don't work it just leaves lots of room for improvement. This week we took notes on polar substances and non polar substances. Polar substances can only combine with polar substances. That is why water does not mix with oil. Water is polar and oil is non-polar. I can definitely improve on finishing more of my lab questions at home so in class the work is more manageable. This week I can definitely say I learned some very interesting facts about pH.


For Science Olympiad this week I worked on picture this for about 1 1/2 hours on Monday  and 15 minutes on Wednesday. We continued with our practice and discussed new techniques to win.

This link helped me understand polar and non-polar a lot better. http://www.school-for-champions.com/chemistry/polar_molecules.htm#.VI5BflWJOuZ

                                          tested substances

                                         household products tested for pH

                                          substances about to be tested for pH