As should be clear from the plot of E vs T, the range of cell potentials observed at a single temperature is not negligible compared to the difference in cell potentials at different temperatures. We can use these ranges to estimate how the voltage reading error affects the calculated thermodynamic values. Instead of using a trendline function to calculate a slope and then ΔS recalculate the slope using only two voltages, at the high and low ranges observed. Slope = ΔE/ ΔT = (E1- E2)/(T1-T2)= E33- E15/18K

From this slope, calculate ΔS and enter below.