# Measuring the Enthalpy Change for the reaction

Measuring the Enthalpy Change for the reaction

between Zinc and Copper Sulphate Solution

Equation:

Zn(s) + Cu2+ (aq) ---------> Cu(s) + Zn2+ (aq)

Results:

This table shows how the temperature is affected by the reaction of Zinc and Copper Sulphate throughout the time interval (Zinc powder is added to the Copper Sulphate solution at the fourth minute).

Zinc Mass: 4.761g

Observation:

1. To start with, the copper sulphate solution is transparent blue colour.
2. At the fourth minute, using the glass rod to stir the solution as the Zinc powder is placed into the solution, the colour changes into dark turquoise and the solution fizzes due to the chemical change.
3. The Zinc powder then dissolves in the solution.
4. As I stir the solution, the colour changes to grey with black precipitate.
5. Then, the solution gradually changes from grey to black with black precipitate.

At the twelfth minute, the black precipitate dissolves yet the solution continues to fizz showing the chemical reaction is still taking place.

After collecting the data and recording my observations, I then draw a linear graph in order to work out the temperature rise which occurred at the fourth minute. I decided to draw my graph landscape as I figured out that drawing the graph landscape is the best method to draw the conclusion and working out the temperature rise as the data are more spread out so I can draw out a more accurate measurement.

After working out the change in temperature from the graph, I will then use the value to calculate the heat given out (in Joules) during the experiment. The equation that I will be using is:

q = mc ΔT

Hence, q = 4.18 x 28.1 x 50.0

= 5872.9 J

Moles of aq copper sulphate used in the experiment:

Volume x concentration    =  50.0 x 0.500      = 0.0250 moles

1000                                  1000

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