QuestionQuestion

8. Determine the mass of NaCl necessary to lower freezing point of 300 mL of distilled water to -10°C:
Mass NaCl needed:
9. Based on the actual mass of NaCl you used (#1), determine the theoretical freezing point of the ice/ saltwater bath:
Theoretical freezing point:
10. Determine the % error for the temperature of your ice/saltwater bath (comparing the temperature you measured, #2, and the theoretical freezing point, #9):
                      (temperature) measured - (temperature) theoretical
% error = ------------------------------------------------------------------------ X 100 Equation 14
                                     (temperature) theoretical
% Error:
II. Molar mass determination of ethylene glycol: cooling curve for pure water
11. Plot cooling curve (temperature VS. time) for water (data in #4):

12. Use a straightedge the data (e.g., a ruler) to draw two straight lines on each cooling curve-one drawn make through the region points after before the the water freezes, and one drawn through the data points that to the y-axis).
The intersection of these two lines is the freezing point (determine by extrapolating this point up water begins freezing (e.g., the region where the curve plateaus).
Freezing point of water:
Trial 1:
Trial 2:
Average:

13. Determine the % error for the freezing point of water (comparing the average temperature you determined in #12 and the actual freezing point; NOTE: use Kelvin):
% Error:
III. Molar mass determination of ethylene glycol: cooling curve for aqueous ethylene glycol solution

14. Mass of water:
Trial 1:
Trial 2:

15. Molality of aqueous ethylene glycol solution:
Trial 1:
Trial 2:

16. Plot cooling curve (temperature vs. time) for water (data in #7):

19. The actual molar mass of ethylene glycol is 62.07 g mol-1. Calculate the % error for your average molar mass:
% Error:

Reflection Questions
1. Provide possible reasons for the % error in the temperature of your ice/saltwater bath (#10, Analysis section):

3. Provide possible experimental errors to explain the % error in your Ti of water (#13):

5. Provide possible experimental errors to explain the % error in your calculated molar mass of ethylene glycol (#19):

Solution PreviewSolution Preview

These solutions may offer step-by-step problem-solving explanations or good writing examples that include modern styles of formatting and construction of bibliographies out of text citations and references. Students may use these solutions for personal skill-building and practice. Unethical use is strictly forbidden.

    By purchasing this solution you'll be able to access the following files:
    Solution.pdf.

    $35.00
    for this solution

    PayPal, G Pay, ApplePay, Amazon Pay, and all major credit cards accepted.

    Find A Tutor

    View available General Chemistry Tutors

    Get College Homework Help.

    Are you sure you don't want to upload any files?

    Fast tutor response requires as much info as possible.

    Decision:
    Upload a file
    Continue without uploading

    SUBMIT YOUR HOMEWORK
    We couldn't find that subject.
    Please select the best match from the list below.

    We'll send you an email right away. If it's not in your inbox, check your spam folder.

    • 1
    • 2
    • 3
    Live Chats