Druyd:Knowledge

Training Calorimetry

Storyboard

To measure the heat capacity or specific heat of a metal, the metal is first submerged in boiling water and then in room temperature water. By analyzing the mass of the water and the changes in temperature, the thermal properties of the metal can be determined.

>Model

ID:(1315, 0)

Mechanisms

Concept

Calorimetry is the practice of measuring heat involved in chemical reactions, physical changes, or heat capacity using a calorimeter. In this process, a well-insulated container is prepared to minimize heat exchange with the environment, and the substance or reaction of interest is placed inside. Once the reaction or process begins, the calorimeter is sealed to ensure no external heat influences the measurement. Temperature changes are carefully monitored with a thermometer or temperature sensor, and the mass and specific heat capacity of the substances involved are recorded. The heat absorbed or released by the substance is then calculated based on the observed temperature changes.

There are different types of calorimetry, such as constant-pressure calorimetry, bomb calorimetry, and differential scanning calorimetry (DSC), each suited for specific types of reactions and measurements. Applications of calorimetry include determining enthalpy changes in chemical reactions, measuring heat capacities and phase transitions, studying metabolic rates in biological systems, and characterizing materials by their thermal properties.

In essence, calorimetry involves preparing the experimental setup, initiating the process, measuring temperature changes precisely, and calculating heat transfer to analyze the thermal properties and behaviors of various substances and reactions.

ID:(15248, 0)

Experiment: container and sample diagram

Description

Insulated calorimeter with a thermometer and sample inside the water. Beside it, a professional metal calorimeter.

ID:(11120, 0)

Experiment: calorimetry procedure

Description

Steps to perform the measurement:

Heat a defined quantity of ERROR:8084 until it reaches its boiling point.
Pour the water into an insulated container and measure its quantity (the hot water temperature ( $T_i$ )).
Weigh a sample of the body mass ( $m$ ) that is at a temperature of the sample temperature ( $T_m$ ).
Place the sample into the container and stir until it reaches the temperature of ERROR:8054.
Calculate the value of the specific heat of the sample ( $c$ ).

Diagram:

ID:(11119, 0)

Model

Concept

ID:(15307, 0)

Calorimetry in liquids and solids

Model

Variables

Symbol

Text

Variable

Value

Units

Calculate

MKS Value

MKS Units

$m$

Body mass

$T_i$

T_i

Hot water temperature

$\Delta T_w$

DT_w

Increase in water temperature

$\Delta Q_m$

DQ_m

Sample cooling

$T_m$

T_m

Sample temperature

$\Delta T_m$

DT_m

Sample temperature reduction

$c$

Specific heat of the sample

J/kg K

$c_w$

c_w

Specific heat of water

J/kg K

$\Delta Q_w$

DQ_w

Water heating

Calculations

Equation

Number

First, select the equation:

, then, select the variable:

Symbol

Equation

Solved

Translated

Calculations

Symbol

Equation

Solved

Translated

Variable

Given

Calculate

Target :

Equation

To be used

Equations

$\Delta T = T_f- T_i$

DT = T_f - T_i

(ID 4381)

$\Delta T = T_f- T_i$

DT = T_f - T_i

(ID 4381)

$\Delta Q = M c \Delta T$

DQ = M * c * DT

The heat supplied to liquid or solid ( $\Delta Q$ ) is related to the temperature variation ( $\Delta T$ ) and the heat capacity ( $C$ ) as follows:

$\Delta Q = C \Delta T$

Where the heat capacity ( $C$ ) can be replaced by the specific heat ( $c$ ) and the mass ( $M$ ) using the following relationship:

$c =\displaystyle\frac{ C }{ M }$

Therefore, we obtain:

$\Delta Q = M c \Delta T$

(ID 11112)

$\Delta Q = M c \Delta T$

DQ = M * c * DT

The heat supplied to liquid or solid ( $\Delta Q$ ) is related to the temperature variation ( $\Delta T$ ) and the heat capacity ( $C$ ) as follows:

$\Delta Q = C \Delta T$

Where the heat capacity ( $C$ ) can be replaced by the specific heat ( $c$ ) and the mass ( $M$ ) using the following relationship:

$c =\displaystyle\frac{ C }{ M }$

Therefore, we obtain:

$\Delta Q = M c \Delta T$

(ID 11112)

$c = c_w \displaystyle\frac{ M_w }{ m }\displaystyle\frac{( T_i - T_f )}{( T_f - T_m )}$

c = c_w * M_w *( T_f - T_i )/( m *( T_m - T_f ))

The relationship between the amount of heat released by the object, represented as the heat difference ( $\Delta Q$ ), with a mass of the body mass ( $m$ ), and the temperatures the specific heat of the sample ( $c$ ), ERROR:8054, and the sample temperature ( $T_m$ ), can be described by the following equation:

This amount of heat is equal to the amount of heat absorbed by the water, which has a mass of ERROR:8084 and temperatures the specific heat of water ( $c_w$ ), the hot water temperature ( $T_i$ ), and ERROR:8054, and can be expressed by the equation:

These two amounts of heat are equal, so we can establish the following equality:

$m c (T_f - T_m) = M c_w (T_i - T_f)$

In this way, we can calculate the value of

$c = c_w \displaystyle\frac{ M_w }{ m }\displaystyle\frac{( T_i - T_f )}{( T_f - T_m )}$

(ID 11117)

$\Delta Q_m = \Delta Q_w$

DQ_m = DQ_w

(ID 15635)

Examples

Mechanisms

(ID 15248)

Experiment: container and sample diagram

Insulated calorimeter with a thermometer and sample inside the water. Beside it, a professional metal calorimeter.

(ID 11120)

Experiment: calorimetry procedure

(ID 11119)

Model

(ID 15307)

ID:(1315, 0)