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Enthalpy of the dissociation of formic acid


elizabeth1997

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Two questions:

1. Calculate the molar enthalpy of neutralization of formic acid, deltaHhcooh+oh.

2. Calculate the molar enthalpy of dissociation of formic acid, deltaHhcooh+h2o.

My initial temperature of HCOOH in degrees celsius is 21.9. My initial temperature of NaOH is 20.8. If i calculated my extrapolated final temperature correctly, then it is 26.9. The pH of formic acid solution before the addition of NaOH is 1.88. 

I calculated the number of moles of H3O+ by using the pH of formic acid, and I got 0.013182567. I don't know how to figure out the initial moles of HCOOH before dissociation, and I need this to determine the number of moles of HCOOH remaining in solution when I added the NaOH.

(nHCOOH)initial = (nHCOOH)remaining + (nH3O)

The relationship to use to find the neutralization of formic acid is: nhcoohdeltaHhcooh+oh + nh30deltaHh30+oh = -(CcaldeltaTcal + cwaterVaciddeltaTacid cwaterVbasedeltaTbase)

The equation to use to find the dissociation of formic acid is Hess' Law.

Extra info if needed: Concentration of HCOOH is 1.0, and concentration of NaOH is 1.1.

I would greatly appreciate the help.

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