Chemical Risk Precautions Lab Report

1. Risk Assessment
Chemical Risk Precautions
Fe(nail) Low glasses, lab coats, gloves
Cu(plate) Low glasses, lab coats, gloves
Zn(powder) Highly flammable keep away from open fire, wear glasses, lab coats, gloves
KNO3(aq) Low glasses, lab coats, gloves
FeSO4(aq) Harmful if swallowed glasses, lab coats, gloves, avoid swallowing
CuSO4(aq) Harmful if swallowed glasses, lab coats, gloves, avoid swallowing
ZnSO4(aq) Harmful if swallowed glasses, lab coats, gloves, avoid swallowing
2. Introduction
An electrochemical cell is an energy source that generate the potential difference between electrodes using redox reactions. Oxidation-reduction reactions are used to ensure e.m.f. in the electrochemical cells. The electromotive force (ε) is the output energy provided by a cell and it is measured in volts (V). The value of e.m.f.

Discussion
1) A balanced chemical reaction:
Zn + CuSO4 ZnSO4 + Cu
A full ionic reaction: Zn0(s) + Cu2+(aq) + SO42-(aq) Zn2+(aq) + SO42-(aq) + Cu0(s)
A net ionic reaction: Zn0(s) + Cu2+(aq) Zn2+(aq) + Cu0(s)
Cu2+ + 2e Cu0 - is an oxidant, reduced
Zn2+ Zn0 + 2e- - is a reductant, oxidized
2)
An iron/zinc cell (Exp.3):
On the cathode (+ve): Fe2+(aq) +2e- Fe0(s) - is an oxidant, reduced
On the anode (-ve):Zn0(s) Zn2+ (aq) + 2e- - is a reductant, oxidized
In the Exp.3 the voltage of the iron electrode (Fe2+) is greater than voltage of zinc electrode (Zn2+): E0 (Zn2+) =-0.763 V and E0 (Fe2+) =-0.44 V. Due to this fact, the iron electrode reacts as an oxidant and it reduced on the cathode.
An iron/copper cell (Exp.4):
On the cathode (+ve): Cu2+(aq) + 2e Cu0(s) - is an oxidant, reduced
On the anode (-ve): Fe0(s) Fe2+(aq) +2e- - is a reductant, oxidized
In the Exp.4, the values of the voltage for iron and copper are E0 (Fe2+) =-0.44 V and E0 (Cu2+)=+0.337 V respectively. In this case, the iron reacted such as a reductant and it oxidized on the