# Experimental Molar Enthalpy of Neutralization for Sodium Hydroxide Solution

by flyingpandacake (student)

Yundi Wang

October 22, 2012

Molar Enthalpy of Neutralization

• For information regarding the problem, prediction, materials and procedure, please see attached

Neutralization Reaction Taking Place

Pre-Lab Calculations – Volume of Sulfuric Acid Needed

Average Initial Temperature of Solutions Calculation

Experimental Molar Enthalpy of Neutralization for Sodium Hydroxide Solution Calculation

Solution

• The experimental molar enthalpy of neutralization for sodium hydroxide solution was found to be

-64±3.3KJ/mol.

Calculation of Uncertainties

34.5±0.2˚C – 25.0±0.2˚C

=9.5±0.2˚C

50±0.2mL + 30±0.2mL

=80±0.2mL

9.5 ± 0.4˚C    =  4.210…%

80 ± 0.4mL   =   0.5%

50 ± 0.2mL   =   0.4%

=5.11…%

=5.1%

Percent Difference

Conclusion

Through a pre-lab calculation the amount of sulfuric acid solution needed was found to be 30.0m±0.2mL. Using this information, a calorimetric lab was conducted to find the molar enthalpy of neutralization for the sodium hydroxide solution. Through molar enthalpy calculations, the experimental molar enthalpy of neutralization for the sodium hydroxide solution was found to be -64.0±3.3KJ/mol; however, the theoretical (actual) molar enthalpy of neutralization for the sodium hydroxide solution is -57KJ/mol. In other words the experimental enthalpy change was -64.0±3.3KJ and the theoretical (actual) enthalpy change was -57KJ. This as a result produced a 12% difference. The various errors will be analyzed in the evaluation.

Evaluation

As discussed earlier in the conclusion, the experimental change in enthalpy is greater than the theoretical (actual) change in enthalpy. This result is quite rare. In general, a typical result for the experimental enthalpy change should yield an outcome lower than the theoretical (actual) value (the reason for this will be discussed later in the conclusion); however, this was not the case in this lab. There are a variety of reasons why the experimental enthalpy change for this lab was greater than the theoretical (actual) enthalpy change.

In general, the main reason for the result seen ...