Shenzhen University Physical Chemistry Experiment Report

Shenzhen University Physical Chemistry Experiment Report

Experiment 5 Determination of combustion heat

Experimenter: Zhu Xiheng, Zhang Feng, He Guangtao Experimental time: 2000/4/7

Temperature: 22.2 °C Atmospheric pressure: 101.6 kPa

First, the purpose and requirements of the experiment:

1. Measuring the heat of combustion of benzoic acid with an oxygen bomb calorimeter

2. Defining the definition of combustion heat and understanding the difference between constant pressure combustion heat and constant volume combustion heat.

3. Understand the role of the main part of the calorimeter and master the experimental techniques of the oxygen bomb calorimeter.

4. Learn the Reynolds graphic method to correct the temperature change value.

Second, instruments and reagents

Third, the data record form

Beckman thermometer reading

Fourth, thinking questions:

1. Why should a solid sample be pressed into a sheet?

A: Because the powdered sample will fly everywhere when it is oxygenated, it will make the experiment fail.

2. In the calorimetric measurement, what other conditions may require the use of the Reynolds temperature correction method?

A: In order to accurately measure the temperature, and the change in temperature before and after is not large, the Reynolds temperature correction method can be used.

3. Use the combustion heat data of Nai to calculate the standard production heat of naphthalene?

A: ΔrHm=∑γiΔcHmi-∑γiΔcHmi