# The calculation of various metals heat using calorimetry

Thermal Physics - Lesson 2 Calorimetry Calorimeters and Calorimetry Measuring the Quantity of Heat Calorimeters and Calorimetry Calorimetry is the science associated with determining the changes in energy of a system by measuring the heat exchanged with the surroundings. A-1 Revised 6/ CALORIMETRY – EXPERIMENT A ENTHALPY OF FORMATION OF MAGNESIUM OXIDE INTRODUCTION This experiment has three primary objectives: 1. Find the heat capacity (Cp) of a calorimeter and contents (calibration). In physics class (and for some, in chemistry class), calorimetry labs are frequently performed in order to determine the heat of reaction or the heat of fusion or the heat of dissolution or even the specific heat capacity of a metal. Laboratory 3: Speci c Heat and Calorimetry Measure the initial temperature of the water in the calorimeter. Use a second ring stand to secure the thermometer in place. After the water in the beaker has been boiling for 10 minutes and the temperature of the metal sample has been stable for 5 minutes record the temperature in the results section.

Thermal Physics - Lesson 2 Calorimetry Calorimeters and Calorimetry Measuring the Quantity of Heat Calorimeters and Calorimetry Calorimetry is the science associated with determining the changes in energy of a system by measuring the heat exchanged with the surroundings.

Now that sounds very textbooky; but in this last part of Lesson 2, we are going to try to make some meaning of this definition of calorimetry.

In physics class and for some, in chemistry classcalorimetry labs are frequently performed in order to determine the heat of reaction or the heat of fusion or the heat of dissolution or even the specific heat capacity of a metal.

These types of labs are rather popular because the equipment is relatively inexpensive and the measurements are usually straightforward.

## The Science of Thermodynamics

In such labs, a calorimeter is used. A calorimeter is a device used to measure the quantity of heat transferred to or from an object. Most students likely do not remember using such a fancy piece of equipment known as a calorimeter. Rather, it is because the calorimeter used in high school science labs is more commonly referred to as a Styrofoam cup. It is a coffee cup calorimeter - usually filled with water. The more sophisticated cases include a lid on the cup with an inserted thermometer and maybe even a stirrer. Coffee Cup Calorimetry So how can such simple equipment be used to measure the quantity of heat gained or lost by a system?

We have learned on the previous pagethat water will change its temperature when it gains or loses energy. So if the mass of water and the temperature change of the water in the coffee cup calorimeter can be measured, the quantity of energy gained or lost by the water can be calculated.

The assumption behind the science of calorimetry is that the energy gained or lost by the water is equal to the energy lost or gained by the object under study. So if an attempt is being made to determine the specific heat of fusion of ice using a coffee cup calorimeter, then the assumption is that the energy gained by the ice when melting is equal to the energy lost by the surrounding water.

It is assumed that there is a heat exchange between the iceand the water in the cup and that no other objects are involved in the heat exchanged. The value of a lid on the coffee cup is that it also reduces the amount of heat exchange between the water and the surrounding air. The more that these other heat exchanges are reduced, the more true that the above mathematical equation will be.

Any error analysis of a calorimetry experiment must take into consideration the flow of heat from system to calorimeter to other parts of the surroundings.

And any design of a calorimeter experiment must give attention to reducing the exchanges of heat between the calorimeter contents and the surroundings.

## Determining the Heat Capacity of Unknown Metals

Bomb Calorimetry The coffee cup calorimeters used in high school science labs provides students with a worthwhile exercise in calorimetry. For situations in which exactness and accuracy is at stake, a more expensive calorimeter is needed. Chemists often use a device known as a bomb calorimeter to measure the heat exchanges associated with chemical reactions, especially combustion reactions.

Having little to nothing to do with bombs of the military variety, a bomb calorimeter includes a reaction chamber where the reaction usually a combustion reaction takes place. The reaction chamber is a strong vessel that can withstand the intense pressure of heated gases with exploding. The chamber is typically filled with mostly oxygen gas and the fuel.OBJECTIVE: To determine the specific heat of various solids by the method of heat transfer.

APPARTUS: Calorimeter with stirrer weighing scale Thermometer boiler (beaker and hotplate) Small pieces of ice two metal solids (made of different materials).

Laboratory 3: Speci c Heat and Calorimetry Introduction Calorimetry is the science of measuring heat. We will use a calorimeter to measure the amount of heat transfered from an water we will be able to determine the amount of heat transfered from the metal to the water and thus calculate the speci c heat of the metal.

The following. Laboratory 3: Speci c Heat and Calorimetry Measure the initial temperature of the water in the calorimeter.

Use a second ring stand to secure the thermometer in place. After the water in the beaker has been boiling for 10 minutes and the temperature of the metal sample has been stable for 5 minutes record the temperature in the results section.

Calorimetry is the mechanism used by scientists to study heat capacity. Calorimetry uses two objects together to measure the temperature and determine heat capacity of different elements. The test is conducted by pouring a specific weight of hot water into a Styrofoam cup.

The equation for the heat capacity of the metal was also different.

## Sciencing Video Vault

It was C P, M = – Δ T CW (B + m CW C P) / (m HM Δ T HM). Lastly, to find the molar mass of the metal, I then divided 25 J/mole K by the heat capacity of the metal, which is the Law of Dulong and Petit. A g piece of metal that had been submerged in boiling water was quickly transferred into mL of water initially at °C.

The final temperature is °C. Use these data to determine the specific heat of the metal. Use this result to identify the metal.

Calorimeters and Calorimetry