Answer Happy

A student performed the experiment as described in the Procedure section. This was what the student's data sheet looked like Solution Mass NaCl (8) Mass % NaCI 1 2 1.211 2.032 3.424 4.500 Mass water (8) 29.672 30.068 29.142 30.312 3.921 6.330 10.51 12.93 Mass of 10.00 mL (9) 10.091 10.178 10.286 10.381 3 4 5 5.739 30.962 10.495 Mass of 10.00 mL of unknown: 10.298 g 1. Determine the concentration (mass % NaCl) for solution 5 and enter it in the table. 2. Use the data in the measured "Mass of 10.00 ml" column to calculate the density of each of the five standard solutions, and enter the answer for solution 1 below. Density of solution 5 g/mL 3. Make a calibration curve (graph) of density (y-axis) vs. concentration in mass % (x-axis) for the five standard solutions. Use Logger Pro (or Google Sheets/Excel) to determine the equation of the best-fit line. Enter the slope and y-intercept of this line below. Hint: Help with Excel/Google Sheets if you cannot use Logger Pro [PDF] w -1 Slope - 9.mL-1. % w Intercept g/mL 4. Calculate the density of the unknown solution. This value should be calculated simply by using the experimental data provided above. g/ml
5. Calculate the concentration (mass %) of your unknown using the slope, the intercept, and the density of the unknown calculated in the previous questions. You may have to increase the number of digits shown by the equation of the line on your graph to 3 or 4. Mass % unknown = %w/w