The pH scale is used to determine the acidity or basicity level of liquid solutions. If a solution scores a pH level of 1-6 it is an acidic solution, 1 being the most acidic and 6 being the least acidic. If a solution rates a pH level of 7 it is a neutral solution, meaning it is neither an acidic nor a basic solution. Lastly, if a solution is 8-14 on the pH scale it is a basic solution, 8 being the least basic and 14 being the most basic. The products that are used on a daily basis in your house can also be acidic solutions, basic solutions, or even neutral solutions.
Food products are likely to be weak acids because food is not slippery, you can eat it which is why it’s a weak acid, and because foods are sour. Cleaning products are predicted to be strong bases because they consist of a very key characteristic of bases; they are slippery. Personal care products are predicted to be neutral solutions because they are not corrosive like acids and bases that can harm your skin.
•Various common household substances
1.Obtain a small sample of each substance to be tested. Place the substance in one well of the 12-well dish. 2.Test the effect of each sample on red litmus and blue litmus to determine if the substance is acidic, basic or neutral. (Make sure if you have a substance from EACH product type) 3.Test each sample with universal indicator paper. Match the color of the universal indicator paper with the indicator chart to determine the approximate pH value of the substance. Record the pH value and classify the substance as a: •strong base (pH=11-14)
•weak base (pH=8-10)
•approximately neutral (pH=7)
•weak acid (pH=4-6)
•strong acid (pH=0-3)
SubstanceProduct TypeRed LitmusBlue LitmuspH PaperpH ValueAnalysis Acid or Base?
ShampooPersonal CareStayed RedPinkStayed OrangepH 4Weak Acid Lemon JuiceFoodStayed RedRedBright RedpH 1Strong Acid
Green TeaFoodStayed RedStayed BlueStayed OrangepH 7Neutral SpriteFoodStayed RedPinkStayed OrangepH 4Weak Acid
MilkFoodLight PurpleStayed BlueYellowpH 7Neutral
DetergentCleaningBlueStayed BlueYellowpH 10Base
WindexCleaningBlueStayed BlueLight GreenpH 9Weak Base
The three classes of household products tested for pH levels in this lab were; cleaning, personal care, and food products. The only personal care product that was tested in this lab was shampoo; which was a very weak acid, it scored 4 on the pH scale, when tested with red litmus it stayed red, but turned pink when tested with blue litmus and stayed orange when tested with pH paper. Lemon juice was the first food product tested it proved to be a very strong acid; red litmus stayed the same color, blue litmus turned red and pH paper turned bright red, scoring a 7 on the pH scale. The second food
product that was tested was green tea which was neutral; it stayed red with red litmus, stayed blue with blue litmus and stayed orange with pH paper and therefore, scored a pH level of 7. The third food product that was tested was Sprite, which was a weak acid, the red litmus stayed red, blue litmus turned pink and the pH paper stayed orange scoring a pH level of 7. The last food product that was tested was milk, which turned out to be neutral, when tested with red litmus it turned light purple, the blue litmus stayed blue and the pH paper turned yellow, which scored a pH level of 7. Lastly, cleaning products were tested. The first cleaning product tested was detergent which was a base, the red litmus turned blue, the blue litmus stayed blue and the pH paper turned yellow, giving it a pH level of 10. The last cleaning product tested was Windex which was a weak base; it turned red litmus blue, kept blue litmus the same color and turned pH paper light green and scored a pH level of 9.
When red litmus paper was tested on substances from the food category they stayed red, except for milk which turned light purple. When tested with blue litmus paper the results varied; lemon juice was red-because it’s an acid, green tea and milk stayed blue-because they’re neutral and -Sprite turned pink-because it’s a weak acid. The results also varied when tested with pH paper; lemon juice turned bright red-because it’s a strong acid, green tea and Sprite stayed orange and milk turned yellow-because it’s a base.
Only one personal care product was tested; shampoo. It showed acidic properties when tested with all three indicators; the red litmus stayed red, the blue litmus turned pink and the pH paper stayed orange. Shampoo resulted to be a weak acid.
The results for cleaning products were very similar. When tested with red litmus detergent and Windex both turned the paper blue. Then, when they were tested with blue litmus both products kept the blue litmus the same color. The only result that varied was when tested with pH paper detergent turned the paper yellow, while Windex turned the paper light green. But in the end they were both bases, just one stronger than the other.
1.Most of the results within the product class are the same, but the results differ within the class of food products. Food products vary from being acids and neutral solutions. Food products which are sour, like lemon juice, turn out to be acids. On the other hand, some food products are neutral such as milk and green tea. 2.Most of the household products are acids, but in general whichever category they fall under they are weak. The reason the acids are weak because these are things that you use in your day-to-day life, if the acidity level is high it can burn through your skin and cause harm. On the other hand, the cleaning products are weak bases because they need to have some acidic properties to them in order to kill bacteria, if it was a strong base it would not have the same affect. 3.There are many possible errors that could have occurred. First, when putting the chosen substance in the 12-well dish, the wooden stick that was touching the substance may have been contaminated with another substance. Secondly, when all the substances were in the 12-well dish, it was possible that one substance could have accidentally touched another substance. Another error that could have occurred is that enough time was not given to see the change of color in the various indicator papers. Also if a person’s fingers were contaminated with another acid, base, or neutral solution it could have altered the pH level found for the substance. To ensure the best and most accurate results this experiment could be conducted once more.
Blue Litmus Paper
Red Litmus Paper