# Ib Chemistry Experiment- Calculating Enthalpy Change

Only available on StudyMode
• Published : March 24, 2013

Text Preview
Chemistry Internal Assessment:
Determining the Enthalpy Change of a Displacement Reaction

AIM:
To determine the enthalpy change for the reaction between copper(II) sulfate and zinc.

BACKGROUND THEORY:
Bond breaking is endothermic while bond forming is exothermic. The reaction between copper(ll) sulfate and zinc is exothermic as the energy required to form the bonds of the products is greater than the energy required to break the bonds of the reactants. In an exothermic reaction, heat is given off to the surroundings; thus, temperature of the surroundings will increase. By measuring the change in the temperature and using the formula Q= mcΔT, we can calculate the enthalpy change of the reaction.

Equation 1: CuSO4 + Zn  ZnSO4
Ionic Equation: Zn (s) + Cu2+ (aq)  Cu (s) + Zn2+ (aq)

MATERIALS/APPARATUS:
* 1 insulated Styrofoam cup
* Copper(II) sulfate solution
* Zinc Powder
* 1 Thermometer
* 1 Stopwatch
* Weighing Boat
* Electronic Balance

VARIABLES:
Independent| Dependent|
Mass of zinc powder and concentration of copper(II) sulfate solution used.| Temperature of the solution|

PROCEDURE:
1. Use a pipette to measure 25.0cm3 of 1.0 M copper(ll) sulfate to the insulated container. 2. Record the temperature every 30 seconds for 2.5 minutes 3. Add the excess zing powder (6g) at exactly 3 minutes

4. Stir and record the temperature every 30 seconds for the following 10 minutes.

DATA COLLECTION AND PROCESSING:
Time (s)| Temperature (°C)| Time| Temperature (°C)|
30| 25| 390| 62|
60| 25| 420| 61|
90| 25| 450| 60|
120| 25| 480| 59|
150| 25| 510| 58|
180| 25| 540| 56|
210| 45| 570| 55|
240| 52| 600| 54|
270| 56| 630| 52|
300| 60| 660| 51|
330| 61.5| 690| 50|
360| 62| 720| 49|

Therefore, based on the graph shown above (representing the raw data), the change in temperature if the reaction had taken place instantaneously with...