A method for measuring the specific heat capacity of a substance using an adiabatic accelerating calorimeter

Abstract

The present application belongs to the field of chemical thermodynamics, and discloses a method for measuring the specific heat capacity of a substance at constant pressure. The method realizes the measurement of the specific heat capacity of the substance through an adiabatic accelerating calorimeter in a heating-waiting-scanning mode, and provides a convenient and effective method for obtaining the specific heat capacity of the substance.

Description

Technical Field

[0001] This invention belongs to the field of chemical thermodynamics. Specifically, it relates to a method for measuring the specific heat capacity of a substance at constant pressure. Background Technology

[0002] The specific heat capacity at constant pressure of a substance is a fundamental physical property data point, often used to determine the energy required to absorb or remove heat during the heating and cooling process of a substance.

[0003] The main methods for measuring the specific heat capacity of a substance include differential scanning calorimetry, the mixing method, and the electrothermal method. This method provides a new operational approach for measuring specific heat capacity while ensuring a certain sample volume and accuracy. Summary of the Invention

[0004] This invention provides a novel method for measuring the specific heat capacity of substances. This method utilizes an adiabatic accelerated calorimeter in a heating-waiting-scanning mode to measure the specific heat capacity of liquids and solids.

[0005] This invention provides an operating method for measuring the specific heat capacity, the specific process of which is as follows: maintaining a suitable ambient temperature and humidity to ensure that the adiabatic accelerated calorimeter is operating under normal working conditions; in 10 mL of mass... m c The test pool filling mass is m 标 The standard sample was installed in the adiabatic accelerated calorimeter and purged with inert gas. The adiabatic accelerated calorimeter was set to the heating-waiting-scanning mode, the heating rate was set to 2K / min, and the upper temperature limit was set to the smaller of the boiling point of the standard sample at a specified pressure and the estimated boiling point of the sample to be tested at a specified pressure, minus 20℃. Heating was then started, and the furnace temperature was recorded during the heating process. T b and test pool temperature T c After the standard sample test is completed, clean the test cell. The filling mass is [missing information]. m 待 The procedure for the test sample is the same as that for the standard sample.

[0006] This invention provides a method for calculating the specific heat capacity, the calculation process of which is as follows: calculate the specific heat capacity of the standard sample and the sample to be tested within the same measurement temperature range. T b - T c The integral values ​​over time are denoted as follows: Q 标 / K , Q 待 / K , KThe average heat transfer coefficient (not required to be calculated) is denoted as Δ, where Δ represents the temperature difference between the upper and lower limits corresponding to the integration time. T The average isobaric specific heat capacity of the standard sample within this temperature range is known. C p标 , J / (g·K); The average isobaric specific heat capacity of the test cell within this temperature range is known. C pc , J / (g·K); According to the energy balance equation, we have [( m c C pc + m 标 C p标 )Δ T ] / [( m c C pc + m 待 C p待 )Δ T ]=( Q 标 / K ) / ( Q 待 / K The average isobaric specific heat capacity of the sample under test within this temperature range was calculated. C p待 =[( m c C pc + m 标 C p标 )×( Q 待 / K ) / ( Q 标 / K ) - m c C pc ] / m 待 , J / (g·K). Detailed Implementation

[0007] The present invention will be described in more detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0008] Example 1: The temperature in the controlled chamber was 30℃. A standard sample weighing 2.0894g was filled into a 10mL test cell (14.4942g). The sample was installed in an adiabatic accelerated calorimeter and purged with nitrogen. The adiabatic accelerated calorimeter was set to the heating-waiting-scanning mode, the heating rate was set to 2K / min, the upper temperature limit was set to 80.0℃, and the initial measurement temperature was 50.0℃. Heating was then started, and the furnace temperature was recorded during the heating process. T b and test pool temperature T c After the standard sample test was completed, the test cell was cleaned, and 1.9616 g of the sample to be tested was filled in. The adiabatic accelerated calorimeter was set to the heating-waiting-scanning mode, the heating rate was set to 2 K / min, the upper temperature limit was set to 80.0℃, and the initial measurement temperature was set to 50.0℃. Heating was then started, and the furnace temperature was recorded during the heating process. T b and test pool temperature T c After the test is completed, the specific heat capacity of the sample to be tested is calculated according to the calculation method for specific heat capacity measurement.

Claims

1. A method for measuring the specific heat capacity of a substance, characterized in that, The specific heat capacity of a substance at a certain temperature and pressure is measured using the heating-waiting-scanning mode of an adiabatic accelerated calorimeter.