Monday, September 30, 2019

Electrochemical cell lab Aim Essay

Aim :- To find out the feasibility of a redox reaction by looking at the cell potential of the reaction . Quantitative observation The table below shows the values of cell potential that were recorded when the experiment was performed Reaction Cell potential (ÂÂ ±0.01V) CuSO4 and ZnSO4 0.99V CuSO4 and AgNO3 0.64V Ag 1.39V Qualitative Observation Reaction Obsevrations CuSO4 and ZnSO4 Copper sulphate turns from clear to blue , whereas zinc sulphate remains colorless CuSO4 and AgNO3 Copper sulphate is blue in color , silver nitrate is colorless Ag Data processing Experiment 1 Zn(s) -> Zn2+ (aq) + 2e- (aq) Cu2+ (aq) + 2e- (aq) -> Cu (s) Cu2+ (aq) + Zn(s) -> Cu(s) + Zn2+ (aq) Experiment 2 Cu(s) -> Cu2+ (aq)+ 2e- (aq) Ag+(aq) + e- (aq) -> Ag(s) Cu(s) + 2Ag+ (aq) -> Cu2+ (Aq) + 2Ag (s) Experiment 3 Zn(s) -> Zn2+ (aq) + 2e- (aq) Ag+ (aq) + e- (aq)-> Ag(s) Zn(s) + 2Ag+ (aq) -> Zn2+ (aq) + 2Ag (s) The table below shows the literature values for the respective cell potential Reaction Cell potential (ÂÂ ±0.01V) CuSO4 and ZnSO4 0.34V CuSO4 and AgNO3 0.46 V. Ag 1.10 V Error percentage = (|difference between the literature and experimental value|)/(the literature value )x100 = (|0.34V – 0.99V|)/(0.34V) x100 = 191.17% We can similarly find the error percentages for other cell potentials also The table below shows the respective error percentages of each of the cell potential Reaction Error percentage CuSO4 and ZnSO4 191.17% CuSO4 and AgNO3 39.13% Ag 16.36% Theory Electrochemical cells In an electrochemical cell, electricity is produced through chemical reactions. There consist two electrodes: – the negative electrode and the positive electrode. At the negative electrode

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