# Calorimetry

Pages: 4 (1068 words) Published: January 18, 2013
CALORIMETRY

INTRODUCTION
Calorimetry is used to determine the heat released or absorbed in a chemical reaction (1).Trustees of darmouth college states that (1) is used to determine the heat released or absorbed in a chemical reaction. To determine the heat released or absorbed in a chemical reaction an instrument called calorimeter is used. A calorimeter is an instrument used for measuring the heat of a reaction during a well defined process (2). Brucat states that (2) a calorimeter is an instrument used for measuring the heat of a reaction during a well defined process. There are two types of calorimeter, the coffee-cup which is the constant pressure calorimeter and the bomb which is the constant volume calorimeter. The objective of calorimetry experiment is for the students to determine the heat capacity of the calorimeter on calibration, the heat absorbed or released by the calorimeter, the heat of reactions of solutions in the calorimeter, and the enthalpy of the reaction. A calorimeter is an adiabatic system so it does not exchange matter and energy with its surrounding which means: qrxn=-qcal

In the experiment the students did, the instrument they used to measure the heat capacity, the heat, and enthalpy of the reaction is the constant pressure calorimeter, wherein the students use a Styrofoam ball and a 6” test tube with a stopper and thermometer inside it. The equations used to determine the heat capacity, enthalpy, heat of reaction, and the heat of the calorimeter is: Ccal=qcal∆T

qrxn=nLR x ∆H
The students are the ones responsible in preparing their own solution. Inside the test tube the students put the reagents used for calibration to determine the heat capacity of the calorimeter. These reagents are: sodium hydroxide and HCl. Then the students measure the temperature with 15 seconds intervals. The students made two trials and determine the change in temperature which is needed for the calculations. After the calibration, the students are...