View the step-by-step solution to:

Question

Please I need a little bit help. I have all the lab.jpg

lab.jpg

earliest
around
flouris
here calle
the First
different
believed
soanding
years ago
modern
in early
PEOPLES
hey
Mary
ally
ed"
my 06 9 - 0. 00406
Using Freezing-Point Depression to Find Molecular Weight
At = Fpt of lauric acid - Fipt of lauric acid + benzoic acid
THE DATA
. Determine the difference in freezing temp
temperatures, At, between the pure lauric acid (t) and
the mixture of lauric acid and benzoic acid (tz). Use the formula, At = t1 - tz.
my = At
KF
=
of
= mot / kg .
2. Calculate molality (m), in mol/kg, using the formula, At = Kr. m (K, = 3.9.C-kg/mol for
lauric acid).
C. kg/ mol
3. Calculate moles of benzoic acid solute, using the answer in Step 2 (in mol/kg) and the mass
Moles of benzoic acid = my * Mass of solvent in ky
shauric aid
(in kg) of lauric acid solvent.
4. Calculate the experimental molecular weight of benzoic acid, in g/mol. Use the original mass
of benzoic acid from the Data and Calculations table, and the moles of benzoic acid you
found in the previous step
motes / 16 * 0. 00406 by
. Determine the accepted molecular weight for benzoic acid from its formula, C&HSCOOH.
motes .
6. Calculate the percent error.
Mole. wt of benzoic acid (experimental) -
Mass in 9
DATA AND CALCULATIONS
motes
Mass of lauric acid
4.06
9
Mass of benzoic acid
Accepted ((6 15 (OOH ) ( 7 * 12. 01 ) + ( 6 * 1-01 ) + ( 2* 16 )
0 . 5 3 4
Freezing temperature of pure lauric acid
44- 1
9 / mo
Freezing point of the benzoic acid-lauric acid
. C
mixture
35-5
1. error =/ Theoretical - Experimental
Freezing temperature depression, At
Theoretical
* 100 %.
. C
Molality, m
mol/kg
Moles of benzoic acid
mol
Molecular weight of benzoic acid (experimental)
g/mol
Molecular weight of benzoic acid (accepted)
Percent error
g/mol
%
v with Vernier
Chemistry with Vernie

Top Answer

t=freezing point of pure solvent(lauric acid)-freezing point of (lauric acid+benzoic... View the full answer

Sign up to view the full answer

Why Join Course Hero?

Course Hero has all the homework and study help you need to succeed! We’ve got course-specific notes, study guides, and practice tests along with expert tutors.

  • -

    Study Documents

    Find the best study resources around, tagged to your specific courses. Share your own to gain free Course Hero access.

    Browse Documents
  • -

    Question & Answers

    Get one-on-one homework help from our expert tutors—available online 24/7. Ask your own questions or browse existing Q&A threads. Satisfaction guaranteed!

    Ask a Question