Short (~25 base pairs) strands of double helix DNA in solution will, at sufficiently high temperature, disassociate into pairs of single strands. The temperature at which 50% of the double strands have broken apart is called the melting temperature T_m. ("Melting" here has nothing to do with conversion from solid to liquid, it simply connotes a change from a more ordered state to a less ordered state.)

The nearest-neighbor method predicts that the melting temperature depends on the concentration, c, of DNA in the solution:

1/T_m = (R/H) log(c/c₀)

where H is the enthalpy of helix formation, R is the gas constant (all per mole), and c₀ is related to the salt and pair adjusted entropy of helix formation.

In order to determine the thermodynamic constants of DNA "unzipping", various concentrations (x, in Moles/L = M) of DNA are prepared and the melting temperature (y, in absolute temperature: [K]elvin) is measured. The melting temperature measurements have an accuracy of 1 K. It is expected that the data will fit inverse natural log relationship:

1/y=B log(x/A)

with constants:

B=R/H

A=c₀

1. Fit this data to an inverse natural log relationship.
2. Consider the nearest-neighbor method's predicted law. Does this evidence (data) confirm or contradict this scientific claim? Support your answer quantitatively.
3. Properly report (sigfigs, error, units) the A and B parameters of the best-fit relationship.
4. The value of the gas constant R is known to be 8.3145 J/(mole·K). Use a spreadsheet to calculate the enthalpy of helix formation, H, from B, and properly report (sigfigs, error, units) the value.
5. Self-document the spreadsheet and turn in a hardcopy of the page.
6. Make a hardcopy plot of the data with best-fit curve. Make an additional hardcopy plot with scales chosen so as to linearize the curve.