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Endothermic and Exothermic Reactions!!!!
INTRODUCTION
In this lab, you will learn how to find out how to determine if a reaction is endothermic or exothermic using the change in temperature. The two reactions done in this lab are:
H3C6H5O7(aq) + 3NaHCO3(s) -> 3CO2(g) + 3H2O(l) + Na3C6H5O7(aq)
and
Mg(s) + 2HCl(aq) -> H2(g) + MgCl2(aq)
Based on the positive or negative change in temperature found using the Tf - Ti, which are the final and initial temperature recordings, the reactions should be classified as either endothermic or exothermic.
NOTES ON PROCEDURES
- The size of the beaker used should be large enough for the entire styrofoam cup to rest in. The 250ml beaker could be too small for the cup used
- Cutting up the strip of Mg before adding it to the HCl provides more accurate results than just adding the intact strip of Mg
- Be sure to clean all of the equiptment well between Parts I and II
QUESTIONS/CALCULATIONS
Which reaction is endothermic? How do you know?
Which reaction is exothermic? How do you know?
In the reaction between HCl and Mg, was the Potential Energy of the products greater or less than that of the reactants? Why?
Could you replace Mg with any metal? If not, what metals could you replace it with?
CMDMX