CP chemistry per. 5
September 17, 2012
i. Beverage Density Lab Report
ii. Purpose: The purpose of this experiment is to determine the percentage of sugar content in beverages. iii. Materials: Distilled water, beverages (juice, soda, sport drinks), Sugar reference solutions (0, 5, 15, ad 20%) 25ml each, Balance, centigram(0.01g precision), Beaker (100-mL), Erlenmeyer flask (125-mL to collect rinse solutions), Pipet(10-mL), Pipet bulb or pipet filler iv. Procedure:
1. Place an empty 100-mL beaker on the balance and hit the “rezero” button and check if the scale reads 0.00 g 2. Suck up 10.00mL of 0% sugar (distilled water) into a pipet and move the liquid to an empty beaker. 3. In data table A record the mass of 0% sugar water sample. 4. Make sure you rezero the balance using the ‘’rezero" button 5. Clean out ant residual solution in the pipet by gently blotting the tip with a paper towel. 6. For the other four sugars reference solutions repeat steps 2-5; start in order from the least concentrated to the most concentrated * Before using the pipet to move the new solution to a beaker, rinse the pipet once with each new solution. * Drain the rinse solutions into an Erlenmeyer flask.
* Don’t forget to rezero the balance prior to each new mass measurement. 7. Calculate the density and record the value in Data Table one Part B
8. Use the procedure in part A to determine the density of two beverages. Record all mass and volume data in Data table B and use clean glassware. Between successive beverage measurements rinse the pipet with the second beverage. v. Pre-Lab Questions
1. If the following mass and volume data are used to calculate the density of solution, how many significant figures are allowed in the calculated density? Mass of solution = 12.53g; volume of solution = 8.27mL. -12.53= 4 sig figs 8.27= 3 sig figs
In the calculated density, three significant figures are...