NAME:______DATE:______PERIOD:____ LAB “Characteristics of Acids and Bases”
PURPOSE: To observe the characteristics of acids and bases
MATERIALS: sheet of white paper (2) 1-cm piece of magnesium test tube rack dropper bottles containing the following 4 small test tubes 0.1 M sodium hydroxide (NaOH) wide-range pH paper 0.1 M hydrochloric acid (HCl) red litmus paper phenolphthalein blue litmus
PROCEDURE:
1. Obtain 2 small test tubes and place a 1-cm strip of magnesium in each. Add 10 drops of HCl to one test tube, and 10 drops of NaOH to the other. Record your observations in the data table.
2. Obtain 2 small test tubes and place 1 drop of phenolphthalein in each. Add 5 drops of HCl to one test tube and 5 drops of NaOH in the other. Record your observations.
3. Obtain 1 strip of wide-range pH paper. Tear the strip in half and lay it on a sheet of white paper.
4. Place a drop of HCl on one of the strips. Using the color code on the side of the vial, record the “pH” value (a scale used to measure the strength of acids and bases) of the acid.
5. Repeat this process for NaOH, using the other strip of pH paper to test it. Record the results.
6. Obtain a strip of red litmus paper, tear it in half, and place both pieces on the sheet of white paper. Place a drop of HCl on one strip and a drop of NaOH on the other. Record the results.
7. Repeat the procedure in step #6 using a strip of blue litmus paper. Record the results.
Additional Information: (Hint, Hint!!)
There is a high concentration of acid in citrus fruits such as lemons and grapefruits.
Many cleaning agents (ammonia, soaps, etc.) contain a base.
Common acids include: HCl, H2SO4, HNO3, HI, HF, HBr
Common bases include: NaOH, KOH, Ba(OH)2, Ca(OH)2 DATA:
CHARACTERISTIC ACID (HCl) BASE (NaOH)
Reaction With Metal? (Yes or No)
Color in Phenolphthalein
pH Value
Color With Red Litmus
Color With Blue Litmus
CONCLUSIONS:
Listed below are several of the characteristics of acids and bases in no particular order. Your goal upon completion of this lab is to use the information from the data section and the “additional information” section to place these characteristics in the appropriate column of the table that follows.
*List of Characteristics: Taste bitter Taste sour pH value less than 7 pH value greater than 7 Feel slippery Turn “hot pink” when phenolphthalein is added Exhibit no color change when phenolphthalein is added React to produce hydrogen ions (H+) React to produce hydroxide ions (OH-) React with metals to produce hydrogen gas Turn red litmus to blue Turn blue litmus to red
CHARACTERISTICS OF ACIDS CHARACTERISTICS OF BASES