Measuring+pH

Name: Date: STEM Middle Academy – 8th Grade Science Block: Measuring pH Procedure: Data:
 * 1) Gather Materials: 50ml Beaker, Litmus Paper
 * 2) Fill beaker with 20ml of water (HOH).
 * 3) Rip off 5cm (2 inch) strip of Litmus paper and dip into water.
 * 4) Compare color change to that on Litmus packaging.
 * 5) Record pH of water in chart below.
 * 6) Repeat process with Sodium Hydroxide (NaOH)
 * 7) Repeat process with Acetic Acid (HCH3CO2)
 * 8) Repeat process with Citric Acid (HC6H7O7)
 * 9) Repeat process with Hydrochloric Acid (HCl)
 * Water (HOH) ||  Sodium Hydroxide (NaOH)  ||  Acetic Acid (HCH3CO2)  ||  Citric Acid (HC6H7O7)  ||  Hydrochloric Acid (HCl)  ||

Data Analysis:
 * 1) Which chemical had the highest pH?  This would make it which type of hydrogen compound?
 * 2) Did water change the color of the Litmus paper?   Why or why not?
 * 3) The acids change the color of the litmus paper to
 * 4) Which acid is the strongest?
 * 5) How many times stronger than water is it?   Remember that pH is a logarithmic scale.
 * 6) Compare acetic Acid to Citric Acid. Which is stronger and by how much? Use data from your experiment to support your claim.