Acid Burn Lab

Experiment #5: Acid Burn!!!
Introduction
The goal of this lab was to correctly prepare a 0.2M solution of NaOH, identify highly acidic household cleaning chemicals, and determine their concentration (molarity) through titrations using the previously prepared 0.2M NaOH solution.
Experimental
First, to create 0.5L of 0.2M solution of NaOH, standard 3M NaOH solution was obtained. Next, calculations were performed to determine the amount 3M NaOH necessary to create 0.5L of the 0.2M solution and, as a result, 33.333ml of the 3M solution was measured and poured into a 600ml beaker. The 33.333ml of 3M solution was then diluted with deionized H2O to a volume of 0.5L, thus theoretically resulting in 0.5L of 0.2M NaOH. Next this solution was used
Multiple titrations were performed with each chemical. Calculations were then performed to determine the concentration of each chemical from its trials and the average molarities from these trials were used to conclude the concentration of each household cleaner. SnoBol had an average concentration of 4.7M, Lysol had an average concentration of 3.1M, and The Works had an average concentration of 6.3M.
Molarity of NaOH
Trial
Mass of KHP used (g)
NaOH used (ml)
Molarity of NaOH (mol/L)
1
0.6129
15.39
0.1950
2
0.6108
14.92
0.2005
Average Molarity of NaOH (M)
0.1977

Sample Calculations
Molarity of NaOH: 0.6129g KHP / (204.22g/mol) / (15.49ml/1000ml) = 0.1950
Average Molarity: (0.1950M + 0.2005M)/2 = 0.1977 pH of Household Cleaners
Cleaner
pH
Drano
11
SnoBol
1
Glass cleaner
9
Parson’s
9
Lysol
1
The Works
1
Comet
In this experiment, a reaction between the acidic household cleaners and a standardized basic solution was used for the titration. In order to obtain standardization of the basic solution (NaOH), a specific volume of the substance was measured and diluted to an approximate concentration; the concentration of this resulting solution was then verified using titrations. Once the standardized NaOH solution was obtained, the household cleaner was first treated with a pH indicator (phenolphthalein) so that the equivalence point, the instant where exactly enough standard solution has been added to the titrand so that their molar concentrations are equal, could be seen. The equivalence point in the titrations conducted was equal to the end point, the instance at which the pH indicator changes color, which allowed the exact point of equivalence to be reached based on physical observation of the titrand. After the indicator had been added to the household cleaner being titrated, the titration was performed and the volume of NaOH required to reach the equivalence/end point was noted; the titration was then repeated twice more to ensure accuracy and precision. To determine the concentration of the household cleaner, first the volume of NaOH used to reach the equivalence point was