Question

Create data columns for:

a. [O2(aq)] in Molarity units
b. KH (using Henry’s Law and PO2 of 0.21 Atm)
c. Ln(KH)
d. 1/T (be sure to convert temperatures to Kelvin)

Conduct a linear regression of your ln (K) vs 1/T data; use these results to find:

a. Delta H in units of J/mole
b. Delta S in units of J/mole-K
c. Comment on the magnitude of your DH compared to the magnitude of various types of
intermolecular forces; is your answer reasonable? What specific intermolecular
interactions are responsible for this release of energy?

Temp.(deg C)	O2 Sol (ppm)
0	14.62
1	14.22
2	13.83
3	13.46
4	13.11
5	12.77
6	12.45
7	12.14
8	11.84
9	11.56
10	11.29
11	11.03
12	10.78
13	10.54
14	10.31
15	10.08
16	9.87
17	9.66
18	9.47
19	9.28
20	9.09
21	8.92
22	8.74
23	8.58
24	8.42
25	8.26
26	8.11
27	7.97
28	7.83
29	7.69
30	7.56
31	7.43
32	7.3
33	7.18
34	7.06
35	6.95
36	6.84
37	6.73
38	6.62
39	6.52
40	6.41

Answer 1

a. ppm means parts per million.

1 ppm of O2 = 1 mg of O2 in 1L

No of moles = Given Wt / Mol Wt

Thus,

Moles = 0.001 g/ 32 g/mol = 3.125*10-5 moles

Thus 1 ppm = 3.125*10-5 moles/L

Using this relation, concentration of O2 for the entire data will calculated.

For instance-

14.62 ppm =  14.62* 3.125*10-5 moles/L = 4.57*10-4 M

b. As per Henry's law-

Solubility = Partial Pressure * Henry's Constant

For solubility = 4.568*10-4 M

Partial Pressure = 0.21 atm

KH = 4.568*10-4 M /0.21 atm = 2.17*10-3 M/atm

Similarly the value of KH can be determined for the entire data.

Temp (deg C)	O2 (ppm)	O2 (M)	KH	ln KH	Temp (K)	1/Temp (1/K)
0	14.62	0.000457	0.002176	-6.13045	273.15	0.003660992
1	14.22	0.000444	0.002116	-6.15819	274.15	0.003647638
2	13.83	0.000432	0.002058	-6.186	275.15	0.003634381
3	13.46	0.000421	0.002003	-6.21312	276.15	0.00362122
4	13.11	0.00041	0.001951	-6.23947	277.15	0.003608154
5	12.77	0.000399	0.0019	-6.26574	278.15	0.003595182
6	12.45	0.000389	0.001853	-6.29112	279.15	0.003582303
7	12.14	0.000379	0.001807	-6.31634	280.15	0.003569516
8	11.84	0.00037	0.001762	-6.34136	281.15	0.00355682
9	11.56	0.000361	0.00172	-6.36529	282.15	0.003544214
10	11.29	0.000353	0.00168	-6.38893	283.15	0.003531697
11	11.03	0.000345	0.001641	-6.41222	284.15	0.003519268
12	10.78	0.000337	0.001604	-6.43515	285.15	0.003506926
13	10.54	0.000329	0.001568	-6.45767	286.15	0.003494671
14	10.31	0.000322	0.001534	-6.47973	287.15	0.0034825
15	10.08	0.000315	0.0015	-6.50229	288.15	0.003470415
16	9.87	0.000308	0.001469	-6.52334	289.15	0.003458413
17	9.66	0.000302	0.001438	-6.54485	290.15	0.003446493
18	9.47	0.000296	0.001409	-6.56471	291.15	0.003434656
19	9.28	0.00029	0.001381	-6.58498	292.15	0.003422899
20	9.09	0.000284	0.001353	-6.60567	293.15	0.003411223
21	8.92	0.000279	0.001327	-6.62455	294.15	0.003399626
22	8.74	0.000273	0.001301	-6.64493	295.15	0.003388108
23	8.58	0.000268	0.001277	-6.66341	296.15	0.003376667
24	8.42	0.000263	0.001253	-6.68223	297.15	0.003365304
25	8.26	0.000258	0.001229	-6.70142	298.15	0.003354016
26	8.11	0.000253	0.001207	-6.71975	299.15	0.003342805
27	7.97	0.000249	0.001186	-6.73716	300.15	0.003331667
28	7.83	0.000245	0.001165	-6.75488	301.15	0.003320604
29	7.69	0.00024	0.001144	-6.77292	302.15	0.003309614
30	7.56	0.000236	0.001125	-6.78997	303.15	0.003298697
31	7.43	0.000232	0.001106	-6.80732	304.15	0.003287851
32	7.3	0.000228	0.001086	-6.82497	305.15	0.003277077
33	7.18	0.000224	0.001068	-6.84154	306.15	0.003266373
34	7.06	0.000221	0.001051	-6.8584	307.15	0.003255738
35	6.95	0.000217	0.001034	-6.8741	308.15	0.003245173
36	6.84	0.000214	0.001018	-6.89006	309.15	0.003234676
37	6.73	0.00021	0.001001	-6.90627	310.15	0.003224246
38	6.62	0.000207	0.000985	-6.92275	311.15	0.003213884
39	6.52	0.000204	0.00097	-6.93797	312.15	0.003203588
40	6.41	0.0002	0.000954	-6.95498	313.15	0.003193358

1/T 0.0031 0.0032 0.0033 0.0034 0.0035 0.0036 0.0037 y = 1745.2x - 12.546 R = 0.9978 in Ink 1000

This is the required plot.