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WorksheetsWEEK 5-3.0 Electrochemistry- (3.1 Galvanic Cell)
Total questions: 15
Worksheet time: 8mins
Which of the species strong oxidizing agent?
Cl2(g) + 2e → 2Cl-(aq) Eocell = + 1.36 V
Cu2+(aq) + 2e → Cu(s) Eocell = + 0.34 V
Ni2+(aq) + 2e → Ni(s) Eocell = – 0.25 V
Ca2+(aq) + 2e → Ca(s) Eocell = – 2.87 V
Cl2(g)
Cu2+(aq)
Ni2+(aq)
Ca2+(aq)
Which is correct to write cell notation
Anode: Zn
Cathode: Ni
Zn2+ (aq,1M) / Zn (s) // Ni (s) / Ni2+ (aq,1M)
Zn (s) /Zn2+ (aq,1M) // Ni2+ (aq,1M) / Ni (s)
Zn2+ (s,1M) / Zn (aq) // Ni (aq) / Ni2+ (s,1M)
Zn (aq) /Zn2+ (s,1M) // Ni2+ (s,1M) / Ni (aq)
Calculate standard cell potential for this equation:
Zn2+(aq) + 2e → Zn(s) Eº = – 0.76 V
Cd2+(aq) + 2e → Cd(s) Eº = – 0.40 V
Eocell = -0.36 V
Eocell = -1.16 V
Eocell = +1.16 V
Eocell = +0.36 V
Based on cell notation below, give the one electrolyte can be used in cathode?
Zn (s) /Zn2+ (aq,1M) // H+ (aq,1M) / H2 (g,1 atm)/graphite (s)
ZnSO4(aq)
H2(aq)
ZnCl2(aq)
HCl(aq)
Based on the cell notation below, give the suitable X can be used ?
X / H2(g,1 atm)/ H+ (aq,1M) // Ag+ (aq,1M) //Ag (s)
Ag (s)
H (s)
Pt (s)
Zn (s)
Which of the pairs give the highest value of voltage cell?
Al3+(aq) + 3e → Al(s) Eocell = - 1.66 V
Cu2+(aq) + 2e → Cu(s) Eocell = + 0.34 V
Ni2+(aq) + 2e → Ni(s) Eocell = – 0.25 V
Br2(l) + 2e → 2Br-(aq) Eocell = + 1.07 V
Al and Ni
Cu and Br2
Al and Br2
Cu and Ni
Arrange the species increasing order oxidizing agent?
Cl2(g) + 2e → 2Cl-(aq) Eocell = + 1.36 V
Cu2+(aq) + 2e → Cu(s) Eocell = + 0.34 V
Ni2+(aq) + 2e → Ni(s) Eocell = – 0.25 V
Ca2+(aq) + 2e → Ca(s) Eocell = – 2.87 V
Ca < Ni < Cu < Cl-
Cl- < Cu < Ni < Ca
Ca2+ < Ni2+ < Cu2+ < Cl2
Cl2 < Cu2+ < Ni2+ < Ca2+
How to increase cell potential, Ecell based on this nearst equation:
Increase temperature
Decrease concentration Ni2+
Increase concentration Ni2+
Choose Eocell anode and cathode the positive value
State one functions of salt bridge
to maintain the movement of electron
to allowing electron to flow and complete the circuit
to separate two electrolyte
to maintain the electrical neutrality of the cell
Which of the statement FALSE about galvanic cell
electron flow from anode(-) to cathode(+)
oxidation occur at anode and reduction occur at cathode
salt bridge can mantain the electrical neutrality of the cell
galvanic cell generate electrical energy to spontaneous reaction
Based on cell notation, write overall equation:
Al(s)/ Al3+(aq,1M) // Pb2+(aq, 1M)/ Pb(s)
Pb(s) + Al3+(aq) ----------> Pb2+(aq) + Al(s)
Pb2+(aq) + Al(s) ---------->Pb(s) + Al3+(aq)
3Pb(s) + 2Al3+(aq) ----------> 3Pb2+(aq) + 2Al(s)
3Pb2+(aq) + 2Al(s) ---------->3Pb(s) + 2Al3+(aq)
What happened if there is no salt bridge?
The reaction stops because the nett increase in negative charge is not neutralized.
The reaction stops because the nett increase in positive charge is not neutralized.
The reaction stops because the nett increase in neutral charge is not neutralized.
The reaction stops because the nett increase in electron charge is not neutralized.
List state for standard electrode potential?
2 atm for gases
1 M for concentration
electrode can be solid and liquid
1g for solid electrode
Predict whether the following reaction occur spontaneously:
2Ag(s) + Br2(g) ----------> 2Ag+(aq) + 2Br-(aq)
EºAg+/Ag = + 0.80 V Eº Br2/Br-= + 1.07 V
Eº cell= + 0.27 V (non-spontaneous)
Eº cell= + 0.27 V (spontaneous)
Eº cell= - 0.37 V (non-spontaneous)
Eº cell= - 0.37 V (spontaneous)
Write cell notation based on this overall equation:
Cu(s) + 2Ag+(aq) ----------> Cu2+(aq) + 2Ag(s)
Cu(s)/ Cu2+(aq,1M) // 2Ag+(aq, 1M)/ 2Ag(s)
2Ag(s)/ 2Ag+(aq,1M) // Cu2+(aq, 1M)/ Cu(s)
Cu(s)/ Cu2+(aq,1M) // Ag+(aq, 1M)/ Ag(s)
Ag(s)/ Ag+(aq,1M) // Cu2+(aq, 1M)/ Cu(s)
