Chmeistry Lab on Energetics

Data collection and processing

Qualitative observation

Before * Blue solution of copper sulfate * Grey zinc powder

During * Blue color solution changes to greyish black * Heat is given out, so the surroundings become hotter.

After * Grey powder remains on the sides of the cup * Precipitate formed at the bottom of the cup

List of chemicals and apparatus used

Chemicals used
Copper sulfate solution, 1 mol dm-3
25g of zinc powder

Apparatus needed
Pipette, 25ml
Pipette filler
Polystyrene cup with lid
Spatula
Digital balance
Thermometer (0-100*C)
Stopwatch

Data collection

Raw Data

| Trial 1 | Trial 2 | Trial 3 | | Temperature/ *C±0.1 | Time/s(±0.1) | | | | 0.0 | 25.6 | 25.9 | 25.7 | 30.0 | 25.6 | 25.9 | 25.7 | 60.0 | 25.5 | 25.9 | 25.7 | 90.0 | 25.5 | 25.9 | 25.7 | 120.0 | 25.6 | 25.9 | 25.7 | 150.0 | 25.5 | 25.9 | 25.7 | 180.0 | 25.5 | 25.9 | 25.7 | 210.0 | 49.4 | 50.2 | 51.2 | 240.0 | 52.2 | 67.6 | 56.9 | 270.0 | 56.5 | 69.8 | 61.2 | 300.0 | 58.9 | 69.3 | 63.8 | 330.0 | 62.5 | 68.4 | 67.9 | 360.0 | 61.7 | 67.9 | 68.5 | 390.0 | 62.8 | 66.8 | 66.5 | 420.0 | 63.2 | 66.2 | 65.2 | 450.0 | 63.9 | 65.1 | 64.2 | 480.0. | 65.5 | 64.1 | 63.1 | 510.0 | 64.1 | 63.3 | 63.1 | 540.0 | 63.7 | 63.3 | 62.2 | 570.0 | 63.5 | 62.6 | 61.9 | 600.0 | 63.2 | 62.0 | 61.3 |

Table showing the temperature and time for the first three trials

After this, a graph was plotted of the average temperature against time. The line produced on this graph was the extrapolated till the 170s mark. The equation of the line was found. The two equations were the equated, the downward sloping and the vertical line and the maximum temperature reached by the reaction was found. Change in temperature was found by subtracting the value obtained by the initial temperature value.

Equation of the downward line

y= -0.0064x+66.857

Equation of vertical line