Question

In this prelab, all answers should be reported to 3 or 4 significant figures.

Scientific notation format = 2.34E-4. The 'E' must be capitalized."

The prelab questions mirror those that you will be doing at the end of the experiment. Bring your work for this prelab assignment to lab and you will have a much easier time completing the Data Analysis Sheet at the end of the experiment.

When preparing your calibration curve for question 4, use the unrounded numbers from questions 1, 2 and 3. If you use the rounded numbers that you entered in prelab, you may not get the correct slope and intercept.

A student performed the experiment at 25°C as described in the coursepack. This was what the student's data sheet looked like. Solution Mass NaCl (9) Mass water (g) Mass % NaCl Mass of 10.00 mL (9) 1 5.651 30.962 D 10.484 4.439 30.312 12.77 10.399 3.226 29.142 9.967 10.288 1.994 30.068 10.162 6.219 3.828 5 1.181 29.672 10.080 Mass of 10.00 mL of unknown: 10.370 g 1. Determine the concentration (mass % NaCl, %w/w) for solution 1 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 1 = g/ml 3. Calculate the density of the unknown solution. This value should be calculated simply by using the experimental data provided above. g/mL

Answer 1

ao we know that mass percentage (mass %) = mass of compound in the O solution X 100 Total mass of the solution Here For solution - Total Mass of the solution - mass of dachig) + mass of water (8) 5.651 g + 30:962 = 36.613 g In question i we have to calculate Mass ). of dace so mass of compound in the solution = mass of dach() in the solution 5.651g dow, .. Gass % of dach - mass of Nacelg) in the solution Xou Total mass of the solution 5.651 8 x 100 36-613 g 0.15u3X100 - 15:43%. Hence a mass ut. Of dace for solution - t = 15.43 Answer. . Mass .. daci(g) =115.43 Mass 7. dacal