ACID-BASE EXPERIMENT
Procedures:
Serial Dilutions (starting with 0.1M solution as stock)
Dilution formula: M1V1 = M2V2 M1: molarity of solution 1 V1: volume of solution 1
M2: molarity of solution 2 V2: volume of solution 2
(Note: be sure to record any calculations and/or observations in the data section)
Step 1: Using the stock solution, 0.1M HCl, and the above equation calculate the appropriate volume necessary to make a 10ml solution of 0.01M HCl. Remember: whenever working in the lab, always add acids into water!
Step 2: Using the 0.01M solution created in Step 1, follow the same procedure outlined in the previous step to make a 10ml solution of 0.001M HCl.
Step 3: With the pH paper available, test the pH of all three acid concentrations: 0.1M, 0.01M, and 0.001M HCl Record your results.
Acid/Base Strengths
Step 4: Using pH paper, test and record the pH values of the following solutions
0.1M HCl, 0.1M NH3, 0.1M HC2H3O2, and 0.1M NaOH.
Combining Strong and Weak Acids/Bases
Step 5: Using equivalent volumes, combine (in a test tube) the following strong and weak acids and bases in all possible combinations of acids with bases and use a data table to record the resulting pH values using a pH meter: 0.1M HCl, 0.1M NH3, 0.1M HC2H3O2, and 0.1M NaOH
Results and Conclusions:
1) How did the concentrations of the three hydrochloric acid solutions compare to each other? How is this related to pH?
2) What is the same about each of the four solutions tested in step 4?
3) Classify the following acids and bases as either strong or weak:
0.1M HCl 0.1M NH3 0.1M HC2H3O2 0.1M NaOH
4) Comparing the four formulas in the previous question with the data you have obtained, what are two characteristics that may be used to define a strong acid/base?
5) Write a balanced chemical equation for each of the reactions observed in Step 5 of the procedures.
6) Based on your observations, what occurs when a strong acid is combined with a strong base? …a strong acid with a weak base? …a weak acid with a strong base? …a weak acid with a weak base?