Household Acids And Bases Lab

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Introduction

The exact or relative pH of a solution can be determined using several different methods. First, acid-base indicators such as red and blue litmus paper are used to find the relative pH or whether a solution is greater than or less than 7 (base and acid respectively). Acids tend to turn blue litmus paper red and have no effect on red litmus paper while bases turn red litmus paper blue and have no effect on blue litmus paper. On the pH scale, a high pH (greater than 7) will have a relatively low concentration of hydronium ion and a relatively high concentration of hydroxide ion, making it a base. A low pH (less than 7) will have a higher concentration of hydronium ion and a relatively low concentration of hydroxide ion. When the concentrations of H+ and OH- are equivalent, the solution is neutral and will have a pH of 7.

Pre Lab Notes

- Use 1.0M Sodium hydroxide in place of drain cleaner

- Use 1.0M Ammonia

-Use orange juice instead of lemon juice

-Mix small amounts of detergent and baking soda in seperate test tubes with water, dissolving as much of the solid as possible

-Put the litmus paper strips on a paper towel, and apply the solution with a pipet

-Use Mr. Mcleod's Diet Coke for a soft drink

Questions / Problems

1. Based on the results of your expirement, what can you say about the red and blue litmus paper, and did the actual pH values correspond to the litmus indicator?

2. Calculate the concentrations of H+ and OH- in all 7 solutions.

3. Predict the results of the lab if Fabreeze (a cleaner) were used as one of the solutions.

4. Explain why ammonia is an acid / base using its dissociation equation.

5. Is baking soda an acid or a base? Explain.

6. Based on your results for Diet Coke, why is soda bad for your teeth?