Alcohol Lab Conclusion Essay

Alcohol Lab Data Conclusion

Objective: The objective of this lab was to find the concentration of an unknown alcohol solution.
Procedure and Data: We found the masses of 10.00 mL of each of the known concentrations of alcohol (minus the beaker mass) by placing the beaker onto the scale, zeroing the scale, and then pouring alcohol into the beaker, repeating for each different concentration solution. Then, using the same method, we found the mass of 10.00 mL of the unknown concentration. We recorded the mass of 10.00 mL of each solution of alcohol, and then we recorded the mass of 10.00 mL of the unknown solution. Percent alcohol is 100 multiplied by the mass of alcohol divided by the total mass of the solution. Using the mass and the given percent mass of ethanol, we found the density of pure ethanol for each known concentration of alcohol, and averaged the three calculated densities to give us a density of pure ethanol (0.8391 g/mL) that we could use to calculate the concentration of the unknown solution. We used this to calculate the volume of ethanol in the unknown test tube (7.918 mL), and used the calculated density of ethanol to convert volume ethanol to mass ethanol in the unknown test tube (6.644 g). Since 10.00 mL of solution measured 8.726 g, we divided the mass of
Then, we compared these two numbers to the class data, of which the mean concentration was 66.30%. Our calculated concentration (using a calculated ethanol density), when compared to the class mean, deviated by ~10% from the mean. Our calculated concentration using the given density of ethanol deviated ~11% off from the mean. Both of these values are just barely within one standard deviation of the mean. This shows that our calculated concentration was not very precise and somewhat