4.3
Lab 4
Gaseous Diffusion, Graham’s Law
EXTRA CREDIT
Jennie Chang (odd)
Allison Yee (Partner)
Sharon Oh (Partner)

CALCULATIONS:
1. Determine experimental distance ratio
Find average of distances for each gas
Sample from data:
(11.0 cm + 10.3cm) / 2 = 10.7
D
A
= M
B
Sample from data: D
A
= 15.0cm
=
1.40 : 1
D
B
= M
A
D
B
= 10.7cm
2. Determine the theoretical distance ratio by using Graham’s Law
Rate A
=
=
36.5g
=
1.47 : 1
Rate B =
Mass A
17.0g
3.
Determine the experimental error (% error)
Equation: E – T
x
100%
T
1.40 – 1.47
x 100% = |-4.76%| =
4.76%
1.47
TABLE OF RESULTS:
Average distance NH
3
15.0 cm
Average distance HCl
10.7 cm
Experimental distance ratio
1:40 : 1
Theoretical distance ratio
1.47 : 1
Percent error
4.76%
DISCUSSION:
This lab was quite confusing at first, but once we got the hang of it, everything went
smoothly. First, we started off the lab wrong. 1) A source of error was we did not read
over all the instructions before starting. We did not put in the HCl and the NH
3
in at the
same time. Suggested improvement:
Read the instructions very carefully before
starting. 2) Another source of error was that we accidentally threw away the cotton ball

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- Spring '10
- Stevens
- Chemistry, Mass, Molecular diffusion